(x+y)/2+(x-y)/3=11/6 (1)4(x+y)-5(x-y)=7 (2)(1)式两边乘以6,即3(x+y)+2(x-y)=11,3x+3y+2x-2y=11,则5x+y=11 (3)(2)式化简,4x+4y-5x+5y=7,则-x+9y=7 (4)(3)式两边乘以9,即45x+9y=99 (5)由(4)-(5),得-46x=-92,解得x=2...