Find the value of y for a given value of x, if y varies directly with x. If y = -252 when x = 84, what is y when x = 74?

Solution:

Given that, y varies directly with x.

⇒ y ∝ x

⇒ y = kx, where k is some constant.

To find y when x = 74:

Given,

y = -252 when x = 84

y = kx

-252 = k × 84

k = -3

When x = 74,

y = k x = 74 × (-3)

y = -222

Hence, the required value is -222.

Find the value of y for a given value of x, if y varies directly with x. If y = –252 when x = 84, what is y when x = 74?

Summary:

If y varies directly with x, given that y = -252 when x = 84, when x = 74 the value of y is -222.