1//解是x=-2/3./0.5x-0.7=6.5-1.3x 0.5x+1.3x=6.5+0.71.8x=7.2x=7.2÷1.8x=41/6(3x-6)=2/5x-31/2x-1-2/5x=-31/10x=-2x=-201-2x/3=3x+1/7-3 等式两边同时乘以21,得 7(1-2x)=3(3x+1)-3*21 7-14x=9x+3-6323x=67 x=67/23...