Suppose y varies directly with x, and y = 8 when x= -2. Find x when y = 20.
x = 10
WRONG AGAIN!
y = kx
when x = -2, y = 8
8 = -2k
k = -4, so we have
y = -4x
when y = 20
20 = -4x
x = -5
y = kx
when x = -2, y = 8
8 = -2k
k = -4, so we have
y = -4x
when y = 20
20 = -4x
x = -5