Respuesta :

Collect like terms.. 7b-9=30 . Add 9 to both sides to isolate b. 7b= 39. Divide both sides by 7. B=39/7 maybe there was a problem is this equation maybe it was 7b+9=30 instead of 7b-9 =30
b-9+6b=30
b+6b=30-9
7b=21
b=21/7
b=3