Question

If y varies directly as x, and y is 18 when x is 5, which expression can be used to find the value of y when x is 11?

5
O y=T8 (11)
18
O y 13 (11)
y-
(18)(5)
O y=
11
11
O y= (18)(5)
5

Answer 1

y=11 * (18/5)

Explanation:

y = kx

Where k is constant of proportionality

18 = k(5)

Hence k = (18/5)

For x = 11, y is....

Y = kx

Y= (18/5) * 11