remember you can do anything to an equation as long as you do it to both sides
1+2b-13=12-4b-2b
1-13+2b=12-6b
-12+2b=12-6b
add 6b both sides
-12+6b+2b=12+6b-6b
-12+8b=12+0
-12+8b=12
add 12 both sides
12-12+8b=12+12
0+8b=24
8b=24
divide both sides by 8
(8b)/8=24/8
(8/8)b=3
1b=3
b=3
