Respuesta :

irspow
perform indicated multiplication on left side to get:

30+6a-9=28a  combine like terms on left side...

6a+21=28a  subtract 21 from both sides...

6a=28a-21  subtract 28a from both sides...

-22a=-21  divide both sides by -22

a=21/22
a=27/22 or 1 5/22 or 1.23