解方程
5x-2.1*4=11.8
3.2*(x+1.5)=8.64
7.8x-6x=7.2
3(x-4)=6
5x-2.1*4=11.8
5x=11.8+8.4
5x=20.2
x=4.04
3.2*(x+1.5)=8.64
3.2x+4.8=8.64
3.2x=3.84
x=1.2
7.8x-6x=7.2
1.8x=7.2
x=4
3(x-4)=6
x-4=2
x=6
5x-2.1*4=11.8
5x-8.4=11.8
5x=20.2
x=4.04
3.2*(x+1.5)=8.64
x+1.5=2.7
x=1.2
7.8x-6x=7.2
1.8x=7.2
x=4
3(x-4)=6
x-4=2
x=6