6x+18=42
6x=42-18
6x=24
x=4
当x=4时,左边=6×4+18=24=右边
∴x=4是原方程的解
5x-2.3=47
5x=47+2.3
5x=49.3
x=9.86
当x=4时,左边=9.86×5-2.3=47=右边
∴x=9.86是原方程的解
一6x+18=42
解:6x=42-18
6x=24
x=4
当x=4时,左边=6×4+18=24=右边
∴x=4是原方程的解
6x+18=42 5x=47+2.3
解:6x=42-18 x=49.3/5
6x=24 x=9.86
x=4 5x9.86-2.3=47
检验:6x4+18=42
6x+18=42
6x=42-18
6x=24
x=4
6x=42-18
6x=24
x=4