x-= 2x-5.8=6.6 解:x=47/40 解:x=6.2 x -(+ )= - x = 解:x=28/21 解:x=11/20 5x - 3x=12 + x = 解:x=6 解: x= - x = x - = 解:x= 解: x= x-= x-(-)= 解:x=1/16+1/12 解 x-13/8=5/8 x=7/48 x=5/8+13/8 x=9/4