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?

Oy- (11
y (11)
(18)(5)
oy-
5
11
2 y = (1865

Answer 1

y = 18/5(11)

Explanation:

If y varies directly as x, this is expressed as;

y∝x

y = kx

k is the constant of proportional constant

if y = 18 and x = 5

18 = 5k

k = 18/5

to get the expression that can be used to find the value of y when x is 11

y = kx

y = 18/5(11)

This gives the required expression