2/3-x+1/2=3/4同时乘以12 8-12x+6 =9 -12x =9-8-6 -12x =-5 x=5/12 啊，刚才看错题目了......
3/4-1/2=2/3*x1/4=2/3*xx=3/8
等于12分之5
x=5/12
2/3-x+1/2=3/4,x=2/3+1/2-3/4=5/12
