Question

How do I solve a+18=7a ?

Answer 1

`a+18=7a`


`18=7a-a`


`18=6a` ⇒
`a= (18)/(6)`


`\boxed {a=3}`

Answer 2

`a+18=7a \ \ \ |\hbox{subtract 7a from both sides} \\ -6a+18=0 \ \ \ |\hbox{subtract 18 from both sides} \\ -6a=-18 \ \ \ |\hbox{divide both sides by (-6)} \\ a=3`