解方程 2/3-8X=3-1/2X 1/6(3X-6)=2/5X-3 4X-3(20-X)=-4 1/3(1-2X)=2/7(3X+1)

2/3-8X=3-(1/2)X
2/3-3=-1/2x+8x
-7/3=(15/2)x
x=-14/45
1/6(3X-6)=2/5X-3
x/2-1=(2/5)x-3
x/2-(2/5)x=-3+1
x/10=-2
x=-20
4X-3(20-X)=-4
4x-60+3x=-4
7x=56
x=8
1/3(1-2X)=2/7(3X+1)
1/3-(2/3)x=(6/7)x+2/7
1/3-2/7=(6/7)x+(2/3)x
1/21=(32/21)x
x=1/32
2.5405/(1+2.7%)^3=约4989.8
(1+2.7%)^3为(1+2.7%)的三次方