两边乘以10得5(x-1)=20-2(x+2)5x-5=20-2x-47x=21x=3
建议写法:(x-1)/2=2-(x+2)/55(x-1)=20-2(x+2)5x-5=16-2x7x=21x=3
2-1/2(x-1)=1/5(x+2) 2-1/2x+1/2=1/5x+2/51/5x+1/2x=2+1/2-2/50.7x=2.1x=3
(x-1)/2=2-(x+2)/55(x-1)=20-2(x+2)5x-5=16-2x7x=21x=3