Question

Y and x have a proportional relationship, and y = 25 when x = 60. What is the value of x when y = 30?

a.25
b.36
c.50
d.72

Answer 1

x= 72

Explanation:

I have a answer book.

Answer 2

the equation governiong this relationship is y = kx. Since y = 25 when x = 60,
25 = 60k, and k=(5/12). Thus, the equation is y = (5/12)x.

If y = 30, then 30 = (5/12)x. Mult. both sides by 12/5 to obtain the value of x:

(12/5)(30) = 360/5 = 72