Work Step by Step
We first combine like terms to obtain that $7b-9=30$. We need to get the b alone, so we cancel out the subtraction by adding 9 on both sides. This leaves us with the equation $7b=39$. We use division to cancel out multiplication, so we divide both sides by 7 to get that b=5.57. We plug 5.57 in for b and confirm that our answer is, indeed, correct.