3x+5(x+y)=36即8x+5y=36............(1)3y+4(x+y)=36即4x+7y=36............(2)(1)-(2)*2得-9y=-36y=4代入(2)得4x+28=364x=8x=2解得x=2y=4
y=2将y=2代入1式得:3x-7*2=1得出:3x=15得出1式*5得:15x-35y=52式*3得:15x-12y=512式-1式得:23y=46得出