Question

If Y varies directly with X solve the following :

Answer 1

a) x = -270

b) y = 304/9 or y = 33.78

c) x = -37.8

Explanation:

y varies directly with x so y = kx

a)

y = kx

k = y/x

k = 10/-30 = -1/3

So

y = -1/3 x

If y = 90 then

90 = -1/3 x

x = 90 *(-3) = -270

b)

k = y/x

k = -19/-4.5

k = 38/9

So

y = 38/9 x

If x = - 8 then

y = 38/9 *(-8)

y = 304/9 or y = 33.78

c)

k = y/x

k = -4.3 / 12.9

k = - 1/3

So

y = -1/3 x

If y = 12.6 then

12.6 = -1/3 x

x = 12.6 *(-3)

x = -37.8