how do I solve a+18=7a ?
\(a+18=7a \ \ \ |\hbox{subtract 7a from both sides} \\ -6a+18=0 \ \ \ |\hbox{subtract 18 from both sides} \\ -6a=-18 \ \ \ |\hbox{divide both sides by (-6)} \\ a=3\)
\(a+18=7a\)\(18=7a-a\)\(18=6a\) ⇒ \(a= \frac{18}{6}\)\(\boxed {a=3}\)
