①式+②式x42x+12x=6+6814x=74x=37/7代入①式2x37/7-4y=64y=74/7-64y=32/7y=8/7
解2x一4y=6.............(1)3x十y=17.................(2)由(1)+(2)×4即14x=74解得x=37/7把x=37/7代入(2)y=17-3×37/7=8/7故方程组的解是x=37/7,y=8/7.
