思路:代数式x-(x-1)/2与(x+2)/5-2的值互为相反数,【x-(x-1)/2】+【(x+2)/5-2】=0,转化为一元一次方程问题解:【x-(x-1)/2】+【(x+2)/5-2】=0 10x-5(x-1)+2(x+2)-20=0 10x-5x+5+2x+4-20=0 10x-5x+2x=20-5-4 7x=11 x=11/7