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
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