Question

The value of y varies directly with x, and y=1 when x=2.

Find y when x=4

Answer 1

Direct variation: y=kx
k = constant of variation

Solve for k when y=1 and x=2
1 = 2 · k
k = 1/2

y = 1/2 · x

Solve for y when x=4
y = (1/2) · (4)
y = 2