All categories

2 years ago

Solve for x. 3x+2=38

Mathematics

2 answers:

SpyIntel [72]2 years ago

8 0

Subtract the two over to cancel it out
3x=36
then divide by 3 to get an answer of
x=12

katrin [286]2 years ago

5 0

x=12

Explanation:

Subtract 2 from both sides which equals: 3x=36

Divide by 3 on both sides which equals x=12

You might be interested in

I need help working question 8. I don't understand how to start it

Lina20 [59]

Why don't you first try to use the cosine law to solve for an angle and then make use of the sin law to solve for the remaining angles.

Cosine law

C^2 = A^2 + B^2 - 2AB(cos C)
Solve for cos C, and then take the inverse of the trig ratio to solve for the angle.

Then set up a proportion like you have done using the sin law and solve for another angle. Knowing the sum of all angles in a triangle add up to 180 degrees, we can easily solve for the remaining angle.

8 0

3 years ago

A number, y, is five times another number, x. The sum of the two numbers is 42. Write the system of equations.

vovikov84 [41]

Answer:

5x+x=42

6x=42

x=7

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers

Determine the best method to solve the system of equations. Then solve the system.

maxonik [38]

Answer:

x=1 y = -1/2

(1,-1/2)

Step-by-step explanation:

7x-2y=8

5x+2y=4

I would use elimination since we have 2y in one equation and -2y in the other

7x-2y=8

5x+2y=4

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

12x = 12

Divide each side by 12

12x/12 = 12/12

x =1

The substitute back into equation 2

5(1) +2y = 4

5 +2y = 4

Subtract 5

5-5+2y = 4-5

2y = -1

Divide by 2

2y/2 = -1/2

y = -1/2

8 0

3 years ago

Read 2 more answers

What is the volume of the prism below?

Triss [41]

Step-by-step explanation:

please subscribe my mom's channel those who subscribed my mom's channel

8 0

2 years ago

The Salk polio vaccine experiment in 1954 focused on the effectiveness of the vaccine in combating paralytic polio. Because it w

sdas [7]

Answer:

Step-by-step explanation:

Hello!

The variables of interest are:

X₁: Number of cases of polio observed in kids that received the placebo vaccine.

n₁= 201299 total children studied

x₁= 110 cases observed

X₂: Number of cases of polio observed in kids that received the experimental vaccine.

n₂= 200745 total children studied

x₂= 33 cases observed

These two variables have a binomial distribution. The parameters of interest, the ones to compare, are the population proportions: p₁ vs p₂

You have to test if the population proportions of children who contracted polio in both groups are different: p₂ ≠ p₁

H₀: p₂ = p₁

H₁: p₂ ≠ p₁

α: 0.05

$Z= \frac{(p'_2-p'_1)-(p_2-p_1)}{\sqrt{p'[\frac{1}{n_1} +\frac{1}{n_2} ]} }$

Sample proportion placebo p'₁= x₁/n₁= 110/201299= 0.0005

Sample proportion vaccine p'₂= x₂/n₂= 33/200745= 0.0002

Pooled sample proportion p'= (x₁+x₂)/(n₁+n₂)= (110+33)/(201299+200745)= 0.0004

$Z_{H_0}= \frac{(0.0002-0.0005)-0}{\sqrt{0.0004[\frac{1}{201299} +\frac{1}{200745} ]} }= -4.76$

This test is two-tailed, using the critical value approach, you have to determine two critical values:

$Z_{\alpha/2}= Z_{0.025}= -1.96$

$Z_{1-\alpha /2}= Z_{0.975}= 1.96$

Then if $Z_{H_0}$ ≤ -1.96 or if $Z_{H_0}$ ≥ 1.96, the decision is to reject the null hypothesis.

If -1.96 < $Z_{H_0}$ < 1.96, the decision is to not reject the null hypothesis.

⇒ $Z_{H_0}$ = -4.76, the decision is to reject the null hypothesis.

H₀: p₂ = p₁

H₁: p₂ ≠ p₁

α: 0.01

$Z= \frac{(p'_2-p'_1)-(p_2-p_1)}{\sqrt{p'[\frac{1}{n_1} +\frac{1}{n_2} ]} }$

The value of $Z_{H_0}$ = -4.76 doesn't change, since we are working with the same samples.

The only thing that changes alongside with the level of significance is the rejection region:

$Z_{\alpha /2}= Z_{0.005}= -2.576$

$Z_{1-\alpha /2}= Z_{0.995}= 2.576$

Then if $Z_{H_0}$ ≤ -2.576or if $Z_{H_0}$ ≥ 2.576, the decision is to reject the null hypothesis.

If -2.576< $Z_{H_0}$ < 2.576, the decision is to not reject the null hypothesis.

⇒ $Z_{H_0}$ = -4.76, the decision is to reject the null hypothesis.

Remember the level of significance (probability of committing type I error) is the probability of rejecting a true null hypothesis. This means that the smaller this value is, the fewer chances you have of discarding the true null hypothesis. But as you know, you cannot just reduce this value to zero because, the smaller α is, the bigger β (probability of committing type II error) becomes.

Rejecting the null hypothesis using different values of α means that there is a high chance that you reached a correct decision (rejecting a false null hypothesis)

I hope this helps!

8 0

3 years ago