x-(x-1)/3=7-(x+3)/5 15x-5(x-1)=7*15-3(x+3) 15x-5x+5=85-3x-9 15x-5x+3x=85-9-5 13x=71 当x=5时 x-(x-1)/3的值与7-(x+3)/5的值相等 x=5
