1) Dada a função, em reais, definida por f(x)=3.x-5. calcule :

a) f(2)=
b) f(-1)=

Answer:

B

Step-by-step explanation:

The inequality will be 35000-320m>0

Answer:

Hey there!

Point K has coordinates of (-2, -5)

Hope this helps :)

Answer:

Point K

Step-by-step explanation:

Since they're asking us to find (-2,-5) first we need to move 2 points to the left and then 5 points down.

Answer:

(9,4) and (12,5)

Step-by-step explanation:

x-3y=-3

Answer:

Step-by-step explanation:

Take the beginning number and add or subtract each transaction to get a new balance. For example,

                  349.45

-     23.42 = 326.03

-     14.95  = 311.08

+   276.50 = 587.58

-    219.93 =  367.65

-       76.84 = 290.81

Answer:

1050

Step-by-step explanation:

Let x = full capacity

[tex]\frac{3}{5} x=\frac{2}{7} x+330[/tex]

Move the variable to the left side by subtracting both sides by [tex]\frac{2}{7} x[/tex]

[tex]\frac{3}{5} x-\frac{2}{7}x=\frac{2}{7} x+330 -\frac{2}{7}x[/tex]

[tex]\frac{3}{5} x-\frac{2}{7} x=330[/tex]

Combine the like terms (don't forget about common denominator)

[tex]\frac{21}{35} x-\frac{10}{35} x=330[/tex]

[tex]\frac{11}{35} x=330[/tex]

Multiply both sides by [tex]\frac{35}{11}[/tex] to isolate the x

[tex](\frac{35}{11})\frac{11}{35} x=330(\frac{35}{11})[/tex]

[tex]x = 1050[/tex]

Answer:

the nearest hundred is 50

Answer:

A) 4x^2+20x+25=(2x)^2+2*(2x)*5+5^2=(2x+5)^2

Area=(side)^2, side=sqrt(area)=sqrt((2x+5)^2)=2x+5

B) 4x^2-9y^2=(2x-3y)(2x+3y), these are the dimensions of the rectangle

A) The length of each side of the square is (2x + 5).

B) The dimensions of the rectangle are (2x - 3y) and (2x + 3y).

Used the concept of a quadratic equation that states,

An algebraic equation with the second degree of the variable is called a Quadratic equation.

Given that,

Part A: The area of a square is [tex](4x^2 + 20x + 25)[/tex] square units.

Part B: The area of a rectangle is [tex](4x^2 - 9y^2)[/tex] square units.

A) Now the length of each side of the square is calculated by factoring the area expression completely,

[tex](4x^2 + 20x + 25)[/tex]

[tex]4x^2 + (10 + 10)x + 25[/tex]

[tex]4x^2 + 10x + 10x + 25[/tex]

[tex]2x (x + 5) + 5(2x + 5)[/tex]

[tex](2x + 5) (2x+5)[/tex]

Hence the length of each side of the square is (2x + 5).

B) the dimensions of the rectangle are calculated by factoring the area expression completely,

[tex](4x^2 - 9y^2)[/tex]

[tex](2x)^2 - (3y)^2[/tex]

[tex](2x - 3y) (2x + 3y)[/tex]

Therefore, the dimensions of the rectangle are (2x - 3y) and (2x + 3y).

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Answer: 0.129

Step-by-step explanation:

Let [tex]\overline{X}[/tex] denotes a random variable that represents the mean weight of babies born.

Population mean : [tex]\mu= \text{3316 grams,}[/tex]

Standard deviation: [tex]\text{324 grams}[/tex]

Sample size = 83

Now, the probability that the mean weight of the sample babies would differ from the population mean by greater than 54 grams will be :

[tex]P(|\mu-\overline{X}|>54)=1-P(\dfrac{-54}{\dfrac{324}{\sqrt{83}}}<\dfrac{\overline{X}-\mu}{\dfrac{\sigma}{\sqrt{n}}}<\dfrac{-54}{\dfrac{324}{\sqrt{83}}})\\\\=1-[P(-1.518<Z<1.518)\ \ \ [Z=\dfrac{\overline{X}-\mu}{\dfrac{\sigma}{\sqrt{n}}}]\\\\=1-[P(Z<1.518)-P(z<-1.518)]\\\\=1-[P(Z<1.518)-(1-P(z<1.518))]\\\\=1-[2P(Z<1.518)-1]=2-2P(Z<1.518)\\\\=2-2(0.9355)\ [\text{By z-table}]\\\\=0.129[/tex]

hence, the required probability =  0.129

Answer:

288 ft³

Step-by-step explanation:

Volume of the pyramid,

base area × height × (1/3)

= (9×8)×12/3

= 72×4

= 288 ft³

Answer:

c=80

Step-by-step explanation:

Based on my reading the critical damping occurs when the discriminant of the quadratic characteristic equation is 0.

So let's see that characteristic equation:

20⁢r^2+c⁢r+80⁢=0

The discriminant can be found by calculating b^2-4aC of ar^2+br+C=0.

a=20

b=c

C=80

c^2-4(20)(80)

We want this to be 0.

c^2-4(20)(80)=0

Simplify:

c^2-6400=0

Add 6400 on both sides:

c^2=6400

Take square root of both sides:

c=80 or c=-80

Based on further reading damping equations in form

a⁢y′⁢′+b⁢y′+C⁢y=0

should have positive coefficients with b also having the possibility of being zero.

Answer:

[tex] y = \frac{3}{4}x - 2 [/tex]

Step-by-step explanation:

Equation of a line is given as [tex] y = mx + b [/tex]

Where,

m = slope of the line = [tex] \frac{y_2 - y_1}{x_2 - x_1} [/tex]

b = y-intercept, which is the value at the point where the line intercepts the y-axis. At this point, x = 0.

Let's find m and b to derive the equation for the line.

[tex] m = \frac{y_2 - y_1}{x_2 - x_1} [/tex]

Use the coordinate pair of any two points on the line. Let's use the following,

[tex] (0, -2) = (x_1, y_1) [/tex] => on the line, when x = 0, y = -2

[tex] (4, 1) = (x_2, y_2) [/tex] => on the line, when x = 4, y = 1

Plug in the values and solve for m

[tex] m = \frac{1 - (-2)}{4 - 0} [/tex]

[tex] m = \frac{1 + 2}{4} [/tex]

[tex] m = \frac{3}{4} [/tex]

b = -2 (the line intercepts the y-axis at this point)

Our equation would be =>

[tex] y = mx + b [/tex]

[tex] y = \frac{3}{4}x + (-2) [/tex]

[tex] y = \frac{3}{4}x - 2 [/tex]

Answer:

Hey there!

q is 1, and n=-2.

q-n=1-(-2), which is 3.

n-q=-2=1, which is -3.

q is 1.

Thus, the least value is n-q, and the greatest value is q-n. Closest to zero would be q.

Let me know if this helps :)

Answer:

Least: n-q

Greatest: q-n

Closest to zero: q

Answer:

Yes , it satisfies the hypothesis and  we can conclude that c = 1 is an element of [0,2]

c = 1 ∈ [0,2]

Step-by-step explanation:

Given that:

[tex]f(x) = 4x^2 -3x + 2, [0, 2][/tex]

which is read as the function of x = 4x² - 3x + 2 along the interval [0,2]

Differentiating the function with respect to x is;

f(x) = 8x - 3

Using the Mean value theorem to see if the function satisfies it, we have:

[tex]f'c = \dfrac{f(b)-f(a)}{b-a}[/tex]

[tex]8c -3 = \dfrac{f(2)-f(0)}{2-0}[/tex]

since the polynomial function is differentiated in [0,2]

[tex]8c -3 = \dfrac{(4(2)^2-3(2)+2)-(4(0)^2-3(0)+2)}{2-0}[/tex]

[tex]8c -3 = \dfrac{(4(4)-3(2)+2)-(4(0)-3(0)+2)}{2-0}[/tex]

[tex]8c -3 = \dfrac{(16-6+2)-(0-0+2)}{2-0}[/tex]

[tex]8c -3 = \dfrac{(12)-(2)}{2}[/tex]

[tex]8c -3 = \dfrac{10}{2}[/tex]

8c -3  = 5

8c = 5+3

8c = 8

c = 8/8

c = 1

Therefore, we can conclude that c = 1 is an element of [0,2]

c = 1 ∈ [0,2]

Answer:

Solution ( Second Attachment ) : - 2.017 + 0.656i

Solution ( First Attachment ) : 16.140 - 5.244i

Step-by-step explanation:

Second Attachment : The quotient of the two expressions would be the following,

[tex]6\left[\cos \left(\frac{2\pi }{5}\right)+i\sin \left(\frac{2\pi \:}{5}\right)\right][/tex] ÷ [tex]2\sqrt{2}\left[\cos \left(\frac{-\pi }{2}\right)+i\sin \left(\frac{-\pi \:}{2}\right)\right][/tex]

So if we want to determine this expression in standard complex form, we can first convert it into trigonometric form, then apply trivial identities. Either that, or we can straight away apply the following identities and substitute,

( 1 ) cos(x) = sin(π / 2 - x)

( 2 ) sin(x) = cos(π / 2 - x)

If cos(x) = sin(π / 2 - x), then cos(2π / 5) = sin(π / 2 - 2π / 5) = sin(π / 10). Respectively sin(2π / 5) = cos(π / 2 - 2π / 5) = cos(π / 10). Let's simplify sin(π / 10) and cos(π / 10) with two more identities,

( 1 ) [tex]\cos \left(\frac{x}{2}\right)=\sqrt{\frac{1+\cos \left(x\right)}{2}}[/tex]

( 2 ) [tex]\sin \left(\frac{x}{2}\right)=\sqrt{\frac{1-\cos \left(x\right)}{2}}[/tex]

These two identities makes sin(π / 10) = [tex]\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}[/tex], and cos(π / 10) = [tex]\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}[/tex].

Therefore cos(2π / 5) = [tex]\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}[/tex], and sin(2π / 5) = [tex]\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}[/tex]. Substitute,

[tex]6\left[ \left\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}+i\left\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}\right][/tex] ÷ [tex]2\sqrt{2}\left[\cos \left(\frac{-\pi }{2}\right)+i\sin \left(\frac{-\pi \:}{2}\right)\right][/tex]

Remember that cos(- π / 2) = 0, and sin(- π / 2) = - 1. Substituting those values,

[tex]6\left[ \left\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}+i\left\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}\right][/tex] ÷ [tex]2\sqrt{2}\left[0-i\right][/tex]

And now simplify this expression to receive our answer,

[tex]6\left[ \left\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}+i\left\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}\right][/tex] ÷ [tex]2\sqrt{2}\left[0-i\right][/tex] = [tex]-\frac{3\sqrt{5+\sqrt{5}}}{4}+\frac{3\sqrt{3-\sqrt{5}}}{4}i[/tex],

[tex]-\frac{3\sqrt{5+\sqrt{5}}}{4}[/tex] = [tex]-2.01749\dots[/tex] and [tex]\:\frac{3\sqrt{3-\sqrt{5}}}{4}[/tex] = [tex]0.65552\dots[/tex]

= [tex]-2.01749+0.65552i[/tex]

As you can see our solution is option c. - 2.01749 was rounded to - 2.017, and 0.65552 was rounded to 0.656.

________________________________________

First Attachment : We know from the previous problem that cos(2π / 5) = [tex]\frac{\sqrt{2}\sqrt{3-\sqrt{5}}}{4}[/tex], sin(2π / 5) = [tex]\frac{\sqrt{2}\sqrt{5+\sqrt{5}}}{4}[/tex], cos(- π / 2) = 0, and sin(- π / 2) = - 1. Substituting we receive a simplified expression,

[tex]6\sqrt{5+\sqrt{5}}-6i\sqrt{3-\sqrt{5}}[/tex]

We know that [tex]6\sqrt{5+\sqrt{5}} = 16.13996\dots[/tex] and [tex]-\:6\sqrt{3-\sqrt{5}} = -5.24419\dots[/tex] . Therefore,

Solution : [tex]16.13996 - 5.24419i[/tex]

Which rounds to about option b.

Answer:

2

Step-by-step explanation:

It is the only one that makes sense

Answer:

16 ft

Step-by-step explanation:

Each edge of wall = √256 ft = 16 ft

Answer:

X-4x+11=8

-3x+12-8=0

-3x+4=0

3x=4

X=4/3

Answer:

x = 4/3 or 1.3

Step-by-step explanation:

Combine like terms

8 = -3x + 12

Move the terms

3x = 12 - 8

Calculate

3x = 4

Divide both sides by 3

x = 4/3

or

x = 1.3

The probability that a randomly selected finishing time is greater than 80 seconds is 0.84.

Mean = 87

Standard deviation = 7

We convert this to standard normal as

P( X < x) = P( Z < x - Mean / SD)

Since, 80 = 87 - 7

80 is one standard deviation below the mean.

Using the empirical rule, about 68% of data falls between 1 standard deviation of the mean. So, 32% is outside the 1 standard deviation of the mean, and 16% is outside to either side.

We have to calculate P( X > 80) = ?

That is probability of all values excluding lower tail of the distribution.

P(X > 80) = 68% + 16%

= 84%

= 0.84

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Complete Question

Find the indicated area under the curve of the standard normal​ distribution, then convert it to a percentage and fill in the blank.

About_____% of the area is between z = - 2.2 and z = 2.2 (or within 2.2 standard deviations of the mean).

About_____% of the area is between z = - 2.2 and z = 2.2 (or within 2.2 standard deviations of the mean).

Answer:

About 97.219% of the area is between z = - 2.2 and z = 2.2 (or within 2.2 standard deviations of the mean).

Step-by-step explanation:

From the question given we can see that they both are the same so 1  will just solve one

   Now the area under this given range can be represented mathematically as

  [tex]P ( -2.2 < z < 2.2) = P(z < 2.2 ) - P(z < -2.2 )[/tex]

Now  from the z-table  

        [tex]p(z < 2.2 ) = 0.9861[/tex]

and

        [tex]p(z < - 2.2 ) = 0.013903[/tex]

So

     [tex]P ( -2.2 < z < 2.2) = 0.9861 - 0.013903[/tex]

     [tex]P ( -2.2 < z < 2.2) = 0.97219[/tex]

So converting to percentage  

     [tex]P ( -2.2 < z < 2.2) = 0.97219 * 100[/tex]

    [tex]P ( -2.2 < z < 2.2) = 97.219 \%[/tex]

Answer:

Step-by-step explanation:

[tex]h = 12 cm\\d = 8cm\\r =d/2 = 8/2 =4\\V = ?\\V =\pi r^2h\\\\V= 3 \times 4^2\times12\\V = 576 cm^3[/tex]

Answer:

Solution : Option B

Step-by-Step Explanation:

We have the following system of equations at hand here.

{ x = 5 cot(t), y = - 3csc(t) + 4 }

Now instead of isolating the t from either equation, let's isolate cot(t) and csc(t) --- Step #1,

x = 5 cot(t) ⇒ x - 5 = cot(t),

y = - 3csc(t) + 4 ⇒ y - 4 = - 3csc(t) ⇒ y - 4 / - 3 = csc(t)

Now let's square these two equations. We know that csc²θ - cot²θ = 1, so let's subtract the equations  as well. --- Step #2

( y - 4 / - 3 )² = (csc(t))²

- ( x - 5 / 1 )² = (cot(t))²  

___________________

(y - 4)² / 9 - x² / 25 = 1

And as we are subtracting the two expressions, this is an example of a hyperbola. Therefore your solution is option b.

Answer:

[tex]x = 7[/tex]

Step-by-step explanation:

We can solve the equation [tex]5x+3+8x-4=90[/tex] by isolating the variable x on one side. To do this, we must simplify the equation.

[tex]5x+3+8x-4=90[/tex]

Combine like terms:

[tex]13x - 1 = 90[/tex]

Add 1 to both sides:

[tex]13x = 91[/tex]

Divide both sides by 13:

[tex]x = 7[/tex]

Hope this helped!

Answer:

x = 7

Step-by-step exxplanation:

5x + 3 + 8x - 4 = 90

5x + 8x = 90 - 3 + 4

13x = 91

x = 91/13

x = 7

probe:

5*7 + 3 + 8*7 - 4 = 90

35 + 3 + 56 - 4 = 90

Answer:

Base area=5*12=60

Height is 4

Perimeter or the base is 2*(12+5)=34

Surface area is 2B+Ph=120+136=256

Answer:

1/9

Step-by-step explanation:

2/6*1/6=2*1/6*6 or 1/9.

Answer:

1/18

Step-by-step explanation:

1. multiply across

2*1 and 6*6

2/36

2. divide by 2 to simplify

2/2 and 36/2

1/18

Answer:

9 hours

Step-by-step explanation:

Since the group of men remains the same, number of hours is proportional to number of radios.

1300/26 = 450/h

h = 26 * 450 / 1300 = 9 hours

Answer:

The number is - 14.5

Step-by-step explanation:

Let the number be x.

ATQ, 15+2x=-14, x=-29/2=-14.5

Answer:

+3.464; -3.464

Step-by-step explanation:

call A = y + 2x + 1 = 0 => y = (1 - 2x)

call B: 4y - 4(x^2) - 12x = -7

=> replace y from A to B =>

=> get delta Δ = (-4^2) - 4*(-4 * 11) = 192

=> Δ > 0 => got 2 No

=> x1 = [tex]\frac{-4 + \sqrt{192} }{2 * -4}[/tex] = [tex]\frac{1 - 2\sqrt{3} }{2}[/tex] = -1.232

=> x2 = [tex]\frac{-4 - \sqrt{192} }{2 * -4}[/tex]=[tex]\frac{1 + 2\sqrt{3} }{2}[/tex]= 2.232

=> replace x from B into A

=> y1 = (1 - 2x) = (1 - 2 * -1.232) = 3.464

=> y2 = (1 - 2x) = (1 - 2 * 2.232) = - 3.464

9514 1404 393

Answer:

  16 mi/h

Step-by-step explanation:

The time for a given leg of the trip is the distance divided by the speed. If t is the speed in traffic, the total trip time is ...

  16/t +47/(t+31) = 2

Multiplying by t(t+31), we get ...

  16(t +31) +47t = 2(t)(t+31)

  2t^2 -t -496 = 0 . . . . put in standard form

  (2t +31)(t -16) = 0 . . . . factor

The positive solution is t = 16.

Johhny's average speed in traffic was 16 mph.