y varies directly with x If y = -4 when x = 2, find y when x
6.
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=kx
step 1
Find the value of k (constant of proportionality)
k=y/x
we have that
y=-4 when x=2
substitute
k=-4/2
k=-2
The equation is
y=-2x
step 2
Find the value of y when x=6
y=-2(6)
y=-12
therefore
the answer is
y=-12