Sapphire and trinity are shopping for school clothes. sapphire has $50 and a coupon for a $10 discount at a boutique where each shirt costs $12. sapphire thinks that she can buy three shirts, but trinity says that sapphire can buy five shirts. the equations they used to model the problem are listed below. solve each equation algebraically, and determine who is correct and why. susan’s equation 12x + 10 = 50 bonnie’s equation 12x − 10 = 50