2x-3y/4+2(x+2y)/5=1 ① 3(2x-3y)/4-x+2y/5+4=0 ②①②整理可得48X+y=20 ③10X-37y=-80 ④③*37+④=1786X=660所以X=330/893 把X带入④得y=2020/893
