A bag contains 2 steel balls and 5 brass balls. The total weight is 13 pounds. If 2 steel balls are added and 2 brass balls are removed, the weight decreases to 12 pounds. How much does each kind of ball weigh?
Solve using system of equations. s=number of steel balls b=number of brass balls 2s+5b=13 4s+3b=12 Multiply first equation by -2 to get -4s-10b=-26 add the two equations -7b=-14 Simplify b=2 now substitute 2 for b in any equation to get s=1.5
