How do you find an equation of variation where y varies directly as x and y = 2 when x = 10, find y when x = -25?

1 Answer
Jul 21, 2016

y = -5

Explanation:

When dealing with variation (or proportion), start by writing down what is given, ie there is a relationship betweeny and x

ypropx

This can be written as an equation by using a constant.

y = kx

k = y/x" Use the given values to find" k

k = 2/10 = 1/5" Write the equation with k"

y = 1/5 x" Now you can find any value"

If x = -25, " " y = (1/5) xx -25

y = -5