Martin needs 3.25 gallons of red paint for his small barn and 1.25 gallons of paint for his shed. he spends $81 on paint. how much does the paint cost per gallon ?

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.