Melissa keeps a jar for holding change. The jar holds 21 coins. All of the coins are quarters and nickels. The total amount in the jar is $3.85. How many quarters are in the jar?
A) n + q = 21 B) .05n + .25q = 3.85 Multiplying A) by -.05 A) -.05n + -.05q = -1.05 then adding this to B) B) .05n + .25q = 3.85 .20q = 2.80 q = 14 quarters n = 7 nickels
