解方程:X=7(X-12)X-0.4X=0.
X=7(X-12)
x=7x-84
6x=84
x=84÷6
x=14
X-0.4X=0.54
0.6x=0.54
x=0.54÷0.6
x=0.9
4x+2(20-x)=54
4x+2(20-x)=54
4x+40-2x=54
4x-2x=54-40
2x=14
x=14/2
x=7
x减0.4x等於多少
0.6x
4x+1/4(100-x)=100 x等於多少
4x+1/4(100-x)=100
16x+100-x=400
15x=300
x=20