8分之1*（X+0.5）=75%1/8(x+0.5)=3/4x+0.5=6x=6-0.5x=5.5希望对你有帮助
8分之1*（X+0.5）=75%X+0.5=8*75%X+0.5=3X=3-0.5X=2.5
1/8 *(x+0.5)=75%1/8 x+ 1/16 =3/42x+1=122x=11x=5.5
