Mark is mixing different color paints for a mural he has been asked to paint in the school
gymnasium. To create the color purple he wants,
Mark mixes r gallons of red paint with b gallons of
blue paint. Red paint costs $25 per gallon and
blue paint costs $22 per gallon. He also needs $65
to spend on paint supplies.
Mark knows the cost of his paint and supplies can
be found using the expression