the operation * is defined on the set R of all real number by 2a +3b ÷ a +b evaluate 2*(3*4)​

Answer:

71

Step-by-step explanation:

Recall the trig ratios

Sine = Opposite over Hypotenuse

Cosine = Adjacent over Hypotenuse

Tangent = Opposite over Adjacent

We are given ∠T's  opposite side length and the adjacent side length.

When dealing with opposite and adjacent we use trig ratio Tangent.

( remember tan = opposite over adjacent )

[tex]tan(x)=\frac{52}{18}[/tex]

* multiply each side by the inverse of tan ( [tex]tan^-^1[/tex] )

[tex](tan)^-^1tan(x)=x\\(tan)^-^1*\frac{52}{18} =70.906508\\x = 70.906508[/tex]

* round to the nearest degree *

We get that x = 71

Answer:

45 rand

Step-by-step explanation:

3 large pizzas is 10 ×3=R30

5 small drinks is 1.50×5=R7.50

tip of R7.50

add all

30+7.50+7.50

=45

Answer:

a. five, twelve, thirteen

9514 1404 393

Answer:

  D.  x = 15; y = 5√3

Step-by-step explanation:

You don't need to know any trig to select the correct answer. You only need to know that the lengths of both sides must be less than the length of the hypotenuse. It is also helpful to know that √3 is about 1.732, so 10√3 ≈ 17.32.

Since x < 10√3, only answer choices A and D are viable.

Since y < 10√3, only answer choice D is viable.

_____

If you want to solve this using trig relations, you can recall that the sides of a 30°-60°-90° triangle have the ratios 1 : √3 : 2. This means short side y is half the length of the hypotenuse 10√3, so y = 5√3. It also means longer side x is √3 times y, so is x = (5√3)√3 = 5·3 = 15.

  x = 15; y = 5√3

Answer:

[tex]\frac{3}{1}[/tex]

Step-by-step explanation:

[tex]\frac{3}{1}[/tex] is equivalent to [tex]\frac{6}{2}[/tex] because 3 x 2 = 1 x 6 = 6. 93 is equivalent to [tex]\frac{6}{2}[/tex] because 9 x 2 = 3 x 6 = 18. 124 is equivalent to [tex]\frac{6}{2}[/tex] because 12 x 2 = 4 x 6 = 24.

I'm pretty sure It'd be 74° <3

Answer:

0.50

Step-by-step explanation:

The question states at least 2 which means 2 or more.

The only applicable numbers to look at would be 2 and 3.

First of all we find 2 since it's missing.

Now all probability distributions must add up to 1.

As we can see there are 0.20, 0.30 and 0.40 which is equal to 0.90. Therefore 1 - 0.90 = 0.10 which would be 2.

Hence, the peobability that x is at least 2 is 0.10 + 0.40 = 0.50.

Answer:

8 phone calls

Step-by-step explanation:

Eduardo spent 4 minutes on the phone while routing 2 phone calls. In all, how many phone calls does Eduardo have to route to spend a total of 16 minutes on the phone? Solve using unit rates.

From the above question:

4 minutes = 2 phone calls

16 minutes = x

Cross Multiply

4 minutes × x = 16 minutes × 2 phone calls

x = 16 minutes × 2 phone calls/4 minutes

x = 8 phone calls

Therefore,

Eduardo has to route 8 phone calls to spend a total of 16 minutes on the phone

Answer:

-8100

Step-by-step explanation:

(2/5)^-2(-3)^4

Given data

and second term

The first term=  (2/5)^-2  and

Second term=(-3)^4

Simplify the first term

(2/5)^-2= 2^-2/ 5^-2= 1/2^2 * 1/5^2

=1/4/ 1/25

=1/4*25/1

=100

Simplify the second term

=(-3)^4

= -81

Hence, 100*81

=-8100

Answer:

See explanation below

Step-by-step explanation:

Question is incomplete. Here's the whole question:

"Two solutions of different concentrations of acid are mixed creating 40 ml of a solution that is 32% acid. one-quarter of the solution is made up of a 20% acid solution. the remaining three-quarters is made up of a solution of unknown concentration, c. equation can be used to determine c, the unknown concentration?

a) 30c + 10(0.2) = 40(0.32)

b) (c) + (0.2) = 40(0.32)

c) (c)( (0.2)) = 40(0.32)

d) 30(c)(10(0.2)) = 40(0.32)"

With this, we can now solve the question.

We have a solution that was made mixing2 different solutions of acid. In this case, we can assume the following:

Solution 1 = 40 mL 32% acid

Solution 2 = 1/4 solution 1, 20% acid

Solution 3 = 3/4 solution 1, c% acid.

Thus we can say:

Solution 1 = Solution 2 + Solution 3     (1)

Now, 1/4 of the volume of solution 1, means that we use 10 mL of a 20%acid, and the remaining 30 mL is the unknown acid.

With this, we can discart option b) and c) because these option are not considering the volume of solution 3 used. Option d is not doing any sum, only multiplications, so, this is not the option to use. We can easily say it's option a, but let's prove it.

In general terms, concentrations and volume are related, and if we have two solutions, the information of these two solutions must be conserved in the resulting solution. In other words:

M₁V₁ = M₂V₂

According to this, the concentration of the unknown acid would be:

30c + 0.2*10 = 40(0.32)

30c + 2 = 12.8

30c = 10.8

c = 0.36

Which means that the concentration of the acid is 36%

Hope this helps

Answer:

A. a) 30c + 10(0.2) = 40(0.32) !

Step-by-step explanation:

EDG

Answer:

Mean = (2.2 + 2.4 + 2.5 + 2.5 + 2.6 + 2.7)/6 = 2.48

Standard deviation = √(summation(x - mean)²/n

n = 6

Summation(x - mean)² = (2.2 - 2.48)^2 + (2.4 - 2.48)^2 + (2.5 - 2.48)^2 + (2.5 - 2.48)^2 + (2.6 - 2.48)^2 + (2.7 - 2.48)^2 = 0.1484

Standard deviation = √(0.1484/6

s = 0.16

Standard error = s/√n = 0.16/√6 = 0.065

Part B

Confidence interval is written as sample mean ± margin of error

Margin of error = z × s/√n

Since sample size is small and population standard deviation is unknown, z for 98% confidence level would be the t score from the student t distribution table. Degree of freedom = n - 1 = 6 - 1 = 5

Therefore, z = 3.365

Margin of error = 3.365 × 0.16/√6 = 0.22

Confidence interval is 2.48 ± 0.22

Part C

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

H0: µ = 2.3

For the alternative hypothesis,

H1: µ > 2.3

This is a right tailed test

Since the number of samples is small and no population standard deviation is given, the distribution is a student's t.

Since n = 6

Degrees of freedom, df = n - 1 = 6 - 1 = 5

t = (x - µ)/(s/√n)

Where

x = sample mean = 2.48

µ = population mean = 2.3

s = samples standard deviation = 0.16

t = (2.48 - 2.3)/(0.16/√6) = 2.76

We would determine the p value using the t test calculator. It becomes

p = 0.02

Assuming significance level, alpha = 0.05.

Since alpha, 0.05 > than the p value, 0.02, then we would reject the null hypothesis. Therefore, At a 5% level of significance, the sample data showed significant evidence that the mean absolute refractory period for all mice when subjected to the same treatment increased.

Step-by-step explanation:

Answer:

3.14

Step-by-step explanation:

[tex]\pi[/tex] or commonly known as Pi is equal to 3.14 so it will fit in between 3 and 4 but closer to 3.

Answer:

a had 8 b had 10 total=180

Step-by-step explanation:

it's weird.  I never really liked word problems but think through it. if each of them had to be the same amount of points, then what does bothe 10 AND 8 fit into?

80. simple.

so that means there were 8 true false questions in section a and 10 multiple choice in b and there was 160 points total because 80 +80 = 160

Answer:

89.804

Step-by-step explanation:

Answer:

[tex]x=7,\\m\angle LKN = 84^{\circ}[/tex]

Step-by-step explanation:

1. For KM to be the angle bisector of angle LKN, it must be bisect LKN into two equal angles. Therefore, we have the following equation:

[tex]9x-21=6x,\\-21=-3x,\\x=\boxed{7}[/tex]

2. Substituting [tex]x=7[/tex]:

[tex]\angle LKN=9x-21+6x=9(7)-21+6(7)=63-21+42=\boxed{84^{\circ}}[/tex]

Answer:

- Take the length and width, and multiply

Step-by-step explanation:

Answer:

Step-by-step explanation:

slope intercept form

y=mx+c

Answer:

A) 20

B) 28%

Step-by-step explanation:

A) In order to find percentages you need to make them in to decimals. 80% as a decimal is .8, if you multiply 25 by the decimal .8, you get 20.

B) To find the percentage all you do is divide, 7/25, this gives you the decimal .28, this as a percentage is 28%.

Answer:

x=3 or x= −7

Step-by-step explanation:

Answer:

C) 3,-7

Step-by-step explanation:

x² + 4x - 21 = 0 (Given)

(x+7)(x-3) = 0 (Factor)

x+7 = 0 and x-3 = 0 (Zero Product Property)

x = -7 and x = 3 (Final Solutions)

Therefore, C is correct

Answer:

7x

Step-by-step explanation:

answer=1/4

explanation ; 6divided by 3/8=0.25    which is equal to 25/100 or 25 divides 25 once and divides 100  4 times giving 1/4

Answer:

21.07 m²

Step-by-step explanation:

Please find the complete question in the attached image

Area of shaded region = area of rectangle - area of semicircle

Area of semicircle = [tex]\frac{1}{2}[/tex]πr²

π = 3.14

r = radius = 14/2 = 7m

the diameter of the semicircle is 14m , thus the radius would be half of the diameter

(1/2) x 3.14 x 7² = 76.93 m^

Area of a rectangle = length x width

width = radius of semicircle = 7

14 x 7 = 98 m²

Area of shaded region =  98 m² -  76.93 m^ = 21.07 m²

Answer:

Step-by-step explanation:

Jackie   you should know that  the supplemental angles always add to 180°  :)

That's like angles  1 & 2  or   55° & 1  .  both are supplemental and add to 180°

Knowing this should make answering this pretty easy. :)

180 = ∠1 + 55

125 = ∠1

∠3 =∠1

∠2 = 55°

since line g is parallel to f , we know all the angles in the same places of line f are identical... got it?

Answer:

it is the hilighted one the one besides it and below it

Step-by-step explanation:

Answer: The answer to this problem is the second choice “As the x-value increases by 1, the y-value decreases by 1/2, the x-intercept is -2.

Have a nice day!