75%x+三分之二x=1
3/4x+2/3x=1
9x+8x=12
17x=12
x=12/17
x+25%=8
x=8-0.25
x=7.75
(1-40%)x=6.3
0.6x=6.3
x=6.3/0.6
x=63/6
x=21/2