a) {2x-11y=73 3x-4y=47 b) {-2x+5y=-10 7x-4y=8 c) {9x+8y=1 5x-6y=11

a) {2x-11y=73 /*3 3x-4y=47 /*(-2) {6x-33y=219 -6x+8y=-94 -25y=125 y=-5 2x+55=73 2x=18 x=9 {y=-5 x=9 b) {-2x+5y=-10 /*7 7x-4y=8 /*2 {-14x+35y=-70 14x-8y=16 27y=-54 y=-2 -2x-10=-10 -2x=20 x=10 {y=-2 x=10 c) {9x+8y=1 /*5 5x-6y=11 /*(-9) {45x+40y=5 -45+54y=-99 94y=-94 y=-1 9x-8=1 9x=9 x=1 {y=-1 x=1