因为互为相反数所以 2(x + 3)/3 + (1 - x)/2 = 04(x + 3) + 3(1 - x) = 04x + 12 + 3 - 3x = 04x - 3x = -3 - 12x = -15
2(x+3)/3+（1-x）/2=0两边乘于6 4（x+3)+3(1-x)=04x+12+3-3x=04x-3x=-12-3x=-15x的值=-15
