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 between#y 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#