x/2-3x=2/3 -(5/2)x=2/3 x=-(4/15)4x-60+3x=6x-63+7x 7x-60=13x-63 x=1/21/2x-1/4x+1/4=2/3x-1 5/12x=5/4 x=3最后一题好像题目不完整