3(X-1)+5(4Y+2)=7
4(X+5)-3(Y+1)=12
=>3x+4y=0
4x-3y=-5
=>12x+16y=0
12x-9y=-15
=>上下合并=>25y=15=>y=3/5
=>把y=3/5带入3x+4y=0=>x=-4/5