Question

the variable Y is directly proportional to the variable X if Y= 32 when X= 20 what is the value of x when y= 40​

Answer 1

25

Explanation:

25

y = kx

32 = 20k

8

5

= k

40 =

8

5

x

5

8

(40) = x

25 = x

Answer 2

x = 25

Explanation:

A directly proportional relationship satisfies a proportion or two equal ratios. You can create a ratio between x and y coordinates written as y/x.

So when y = 32 and x= 20, the ratio is 32/20. If y = 40, what is x? This is the ratio 40/x. Set them equal in a proportion. Then cross multiply to solve for x.

`(32)/(20) = (40)/(x)`

32(x) = 20(40)

32x = 800

x = 25