In a class of c children,2/5 are boys What fraction are girls?

Answer:

Yes, you are as far as I can tell it looks right to me,

Answer:

a) [tex]cos(\alpha)=-\frac{3}{5}\\[/tex]

b)  [tex]\sin(\beta)= \frac{\sqrt{3} }{2}[/tex]

c) [tex]\frac{4+3\sqrt{3} }{10}\\[/tex]

d)  [tex]\alpha\approx 53.1^o[/tex]

Step-by-step explanation:

a) The problem tells us that angle [tex]\alpha[/tex] is in the second quadrant. We know that in that quadrant the cosine is negative.

We can use the Pythagorean identity:

[tex]tan^2(\alpha)+1=sec^2(\alpha)\\(-\frac{4}{3})^2 +1=sec^2(\alpha)\\sec^2(\alpha)=\frac{16}{9} +1\\sec^2(\alpha)=\frac{25}{9} \\sec(\alpha) =+/- \frac{5}{3}\\cos(\alpha)=+/- \frac{3}{5}[/tex]

Where we have used that the secant of an angle is the reciprocal of the cos of the angle.

Since we know that the cosine must be negative because the angle is in the second quadrant, then we take the negative answer:

[tex]cos(\alpha)=-\frac{3}{5}[/tex]

b) This angle is in the first quadrant (where the sine function is positive. They give us the value of the cosine of the angle, so we can use the Pythagorean identity to find the value of the sine of that angle:

[tex]cos (\beta)=\frac{1}{2} \\\\sin^2(\beta)=1-cos^2(\beta)\\sin^2(\beta)=1-\frac{1}{4} \\\\sin^2(\beta)=\frac{3}{4} \\sin(\beta)=+/- \frac{\sqrt{3} }{2} \\sin(\beta)= \frac{\sqrt{3} }{2}[/tex]

where we took the positive value, since we know that the angle is in the first quadrant.

c) We can now find [tex]sin(\alpha -\beta)[/tex] by using the identity:

[tex]sin(\alpha -\beta)=sin(\alpha)\,cos(\beta)-cos(\alpha)\,sin(\beta)\\[/tex]

Notice that we need to find [tex]sin(\alpha)[/tex], which we do via the Pythagorean identity and knowing the value of the cosine found in part a) above:

[tex]sin(\alpha)=\sqrt{1-cos^2(\alpha)} \\sin(\alpha)=\sqrt{1-\frac{9}{25} )} \\sin(\alpha)=\sqrt{\frac{16}{25} )} \\sin(\alpha)=\frac{4}{5}[/tex]

Then:

[tex]sin(\alpha -\beta)=\frac{4}{5}\,\frac{1}{2} -(-\frac{3}{5}) \,\frac{\sqrt{3} }{2} \\sin(\alpha -\beta)=\frac{2}{5}+\frac{3\sqrt{3} }{10}=\frac{4+3\sqrt{3} }{10}[/tex]

d)

Since [tex]sin(\alpha)=\frac{4}{5}[/tex]

then  [tex]\alpha=arcsin(\frac{4}{5} )\approx 53.1^o[/tex]

Hey there! :)

Answer:

56.7 kg.

Step-by-step explanation:

Use the density formula to solve for the mass:

D = m/V.

Rearrange in terms of mass, or 'm':

DV = m.

Solve for the volume:

0.06 × 0.9 × 1.5 = 0.081 m³.

Plug this into the equation along with the density:

700 × 0.081 = 56.7 kg.

Answer: 5x + 1

Step-by-step explanation:

f(x) - g(x)

(3x + 2) - (-2x + 1)       Here you distribute the negative sign to (-2x + 1)

3x + 2 + 2x - 1            Here you combine like terms

5x + 1                         This is the answer.

Answer:

D

Step-by-step explanation:

4x^4+3x^2-3x^3-3x+1

Answer:

22

Step-by-step explanation:

In this sequence, the next number is found by adding 4.

Answer:

22

Step-by-step explanation:

10 - 6 = 4

so, all next numbers have to be added by 4

Answer:

I think it's D because the line AC looks like it is splitting the rectangle in half. I think this is right since the angles are congruent. (Angle BAC and Angle ACD)

Answer:

33.3%

Step-by-step explanation:

the increase in price was $22.  Find the ratio

$22

-------

$66

which comes out to 0.33333, or 33.3%.

The percent change in the price of the item is 33.3%.

Answer:

It could be 3.3 i'm not to sure- but the other answer was incorrect

Step-by-step explanation:

there are 53 children in the family gathering

Answer:

C = 53

Step-by-step explanation:

WHAT WE KNOW

m + w + c =100

2w - 2 = m

6 + w + m = c

-------------------------

FIND C

Answer:

The found values are:

A = 1/3

B = -8/3

Step-by-step explanation:

We know that general equation is given by:

y = mx + c

where m is the slope and c is a constant.

x + 3y = -5

y = -(1/3)x - 1/3(5)

Slop of the equation is -(1/3). As parallel line have same slope substitute it in the first equation:

Ax + By = 3

By = -Ax - 3

By = (1/3)x - 3

Hence, A = 1/3

Substitute point (-7,2) into the equation:

B(2) = (1/3)(-7) -3

B(2) = -7/3 - 3

B(2) = -16/3

B = -16/6

B = -8/3

Answer:

15/163

Step-by-step explanation: I dont have one

Answer:

i think its D

Step-by-step explanation:

Answer:

25:16

Step-by-step explanation:

i think its right

Answer:

C. -3

Step-by-step explanation:

Plugging both of those points into the slope formula gets you a slope of -3.

Answer:

≈ 68.2°

Step-by-step explanation:

tan X= 20/8

tan X= 2.5

x= tan ⁻¹ 2.5

x ≈ 68.2°

Answer:

Step-by-step explanation:

 To find the size of YXZ we should use some trigonometry but first let's find the length of YZ

(XZ)²+(ZY)²=(YX)²

YX=[tex]\sqrt{20^{2}+8^{2} }[/tex]

    =4[tex]\sqrt{29}[/tex]

Answer: B

Step-by-step explanation:

Makes the most sense out of all the options because it’s the most random or unpredictable

Answer: 260

Step-by-step explanation: When we 200 times 130% we will get 260.

Answer:

Answer:

The y in the second equation

Step-by-step explanation:

hope this helps

Answer:

Step-by-step explanation:

find the slope

[tex]\frac{4-8}{-5-(-3)} =\frac{-4}{-2} \\\\slope=2\\y=mx+b\\y=2x+b\\[/tex]

take a coordinate to fill in

[tex](-5,4)\\y=-5\\x=4\\-5=2(4)+b\\-5=8+b-8 -8\\-13=b\\[/tex]

this means that the equation is y=2x-13

and if you add m and b

you get :-11

I HOPE THIS HELPS

Answer:

7/2

Step-by-step explanation:

Let $A = (-3,8)$ and $B = (-5,4)$. The midpoint of $\overline{AB}$ is $\left( \frac{(-3) + (-5)}{2}, \frac{8 + 4}{2} \right) = (-4,6)$.

The slope of $\overline{AB}$ is $\frac{8 - 4}{(-3) - (-5)} = 2$, so the slope of the perpendicular bisector of $\overline{AB}$ is $-\frac{1}{2}$. Therefore, the equation of the perpendicular bisector is given by

\[y - 6 = -\frac{1}{2} (x + 4).\]Isolating $y,$ we find

\[y = -\frac{1}{2} x + 4.\]

Answer:

2/$5.00

Step-by-step explanation:

It's the only one that makes sense

Answer:

4,10

It is the only option on the table

Step-by-step explanation:

Answer:

(a) y = -3/5 x + 13/5

(b) y = 5/3 x + 1/3

Step-by-step explanation:

(a) The slope of the tangent line is dy/dx.  Use implicit differentiation:

x² + y² + 4x + 6y − 21 = 0

2x + 2y dy/dx + 4 + 6 dy/x = 0

2x + 4 + (2y + 6) dy/dx = 0

x + 2 + (y + 3) dy/dx = 0

(y + 3) dy/dx = -(x + 2)

dy/dx = -(x + 2) / (y + 3)

At the point (1, 2), the slope is:

dy/dx = -(1 + 2) / (2 + 3)

dy/dx = -3/5

Using point-slope form of a line:

y − 2 = -3/5 (x − 1)

Simplifying to slope-intercept form:

y − 2 = -3/5 x + 3/5

y = -3/5 x + 13/5

(b) The normal line is perpendicular to the tangent line, so its slope is 5/3.  It also passes through the point (1, 2), so point-slope form of the line is:

y − 2 = 5/3 (x − 1)

Simplifying to slope-intercept form:

y − 2 = 5/3 x − 5/3

y = 5/3 x + 1/3

Graphing is the least accurate method for solving systems of equations, and it may only give an approximate answer. Hence, option A is the right choice.

A system of equations is made up of two or more equations that are solved at the same time.

There are three ways to solve a system of equations:

In the question, we are asked which method for solving systems of equations is the least accurate and may only give an approximate answer.

We have discussed all methods above.

Of these methods, when solving manually, as the degree of the equation gets bigger and bigger, the graphing of equations will become difficult, and thus the graphing method will be the least accurate.

Thus, graphing is the least accurate method for solving systems of equations, and it may only give an approximate answer. Hence, option A is the right choice.

Learn more about solving a system of equations at

https://brainly.com/question/7808225

#SPJ2

Answer:

0.16 P(Yellow or Brown)=0.16

Answer: 0.44

Step-by-step explanation:

0.4 + 0.28 = 0.68

1.00 - 0.68 = 0.32

0.32 divided by 2.0 = 0.16

Total answer is 0.44

GLAD TO HELP:)

HAVE A NICE DAY!

BTW: I WAS DOING A TEST, BUT TOOK MY TIME TO HELP YOU! :)

PLEASE BRAINLEST ME!

Answer:

There are 9 llamas.

Step-by-step explanation:

For Billy, we have to find a number that is divisible by four, because he has one group of lambs, and 3 times as many llamas, which gives us 4 groups altogether. The number must be below 10 in order to not go above 17 when Milly's number of animals are included, but above 4 itself in order to reach the target of 17 in the first place.

As you can guess, the only number that fits all the criteria is 8. It's divisible by 4 and below 10, but above 4 itself.

If Billy has three times as many llamas as lambs, then he must have 2 lambs, and 6 llamas, as 2 × 3 = 6.

If we know that Billy has 8 animals, then we also know that Milly must have 9 animals, as 17 - 8 = 9.

We also know that Milly has 3 groups of animals; one group of llamas, and two groups of lambs, meaning we divide the number of animals she has by 3.

9 ÷ 3 = 3.

This tells us Milly has just 3 llamas, because 3 is one group of 9, and 3 × 2 = 6,  because she has twice the amount of lambs.

Billy has 2 lambs and 6 llamas.

Milly has 6 lambs and 3 llamas.

The amount of lambs is irrelevant to our final answer, so we can disregard them and do a final sum of 6 + 3 = 9, which gives us our answer.

Answer:

Billy: Has 4 lots of animals

Milly: Has 3 lots of animals

17 animals in total means that Billy must have 4 lots of 2 (8 animals) and Milly must have 3 lots of 3 (9 animals) So Billy has 6 llamas and Milly has 3, giving 9 llamas in total

Answer:

19.625 cm^2

Step-by-step explanation:

The volume of a cylinder is given by

V = pi r^2 h

V = 3.14 * 5^2 * .25

V =19.625 cm^2

Answer:

median: 90

mode: 91

mean: 84.2 or round it to 84

Step-by-step explanation:

Let me know if this helps! have a great day! :)

Answer:

a) Median = 91

b) mode = 91

c)Mean 84.2

Step-by-step explanation:

a) Median is the middle term. So, 6th term

Median = 91

b) Mode is the score which occurs more number of times

91 occurs 3 times

Mode = 91

c) Mean= sum of all data's/Number of data's

            = 85 + 91 + 48 +98 + 99 /5

            = 421/5

  Mean = 84.2

Answer:

segment FG = one half segment FI, segment FH = one half segment FE, and segment HG = one half segment EI; ΔHFG ~ ΔEFI  

Step-by-step explanation:

In the picture attached, the triangles are shown.

After the dilation and reflection, there is proportionality between segment FG and segment FI, segment FH and segment FE, and segment HG  and segment EI. More specifically:

Answer:

segment FG = one half segment FI, segment FH = one half segment FE, and segment HG = one half segment EI; ΔHFG ~ ΔEFI  

Step-by-step explanation:

In the picture attached, the triangles are shown.

After the dilation and reflection, there is proportionality between segment FG and segment FI, segment FH and segment FE, and segment HG  and segment EI. More specifically:

FG = 1/2*FI

FH = 1/2*FE

HG = 1/2*EI

This answer is right! took the test on FLVS and confirmed it :)

Answer:

Applies are £0.50 each and bananas £0.80 each.

Step-by-step explanation:

Represent the numbers of apples and bananas by a and b respectively.

Then:

5a + 4b = £5.70, and:

4a + 2b = £3.60

Let's solve this system using elimination by addition/subtraction.  Multiply the 2nd equation by -2, obtaining the equivalent system

5a + 4b = £5.70

-8a  - 4b = -£7.20

--------------------------

-3a         =  -£1.50

Dividing both sides by -3, we get £0.50.  Apples are £0.50 apiece.

How much are bananas per piece?  Use the first equation; substitute £0.50 for a:

5(£0.50) + 4b = £5.70, or

                  4b = £3.20.  Then b = £0.80.

Applies are £0.50 each and bananas £0.80 each.

Answer:

1. equilateral triangle

2. rectangle

3. circle area

4. trapezoid

5. circle circumference

6. parallelogram

7. regular polygon

8. triangle

Hope that helps.