解方程:7x+2x=0.81;4(x-6)=36;2x+0.2xX2=36

问题描述:

解方程:7x+2x=0.81;4(x-6)=36;2x+0.2xX2=36

7x+2x=0.81
9X=0.81
X=0.09
4(x-6)=36;
x-6=9
x=3
2x+0.2xX2=36
2.4x=36
x=15