226k views
4 votes
Suppose y varies inversely with x, and y = 18 when x = 12. What is the value of x when y = 24? NO LINKS OR ANSWERING YOU DON'T KNOW?

a. 24
b. 9
c. 12
d. 18​

User FortyTwo
by
8.4k points

2 Answers

5 votes

Answer:

B. 9

Explanation:

We are given that y varies inversely with x. Recall that inverse variation has the form:


\displaystyle y=(k)/(x)

Where k is the constant of variation.

We are given that y = 18 when x = 12. Hence:


\displaystyle (18)=(k)/((12))

Solve for k. Multiply both sides by 12:


k=12(18)=216

Thus, our equation is:


\displaystyle y=(216)/(x)

We want to find x when y = 24. Substitute:


\displaystyle (24)/(1)=(216)/(x)

Cross-multiply:


24x=216

Divide both sides by 24. Hence:


x=9

Our answer is B.

User Gbr
by
7.8k points
3 votes

Answer:

B

Explanation:

Given that y varies inversely with x then the equation relating them is

y =
(k)/(x) ← k is the constant of variation

To find k use the condition y = 18 when x = 12 , then

18 =
(k)/(12) ( multiply both sides by 12 )

216 = k

y =
(216)/(x) ← equation of variation

When y = 24 , then

24 =
(216)/(x) ( multiply both sides by x )

24x = 216 ( divide both sides by 24 )

x = 9

User Scott Lin
by
7.3k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories