Expert: Richard J. Raridon - 2/15/2005

Question
please explain 3-4b=10b+10
also 7d-13=3d+7 and one more please 12+1.5a=3a

Answer
You can add or subtract the same thing from both sides of an equals sign without changing the answer.  You can also multiply or divide both sides by the same thing without changing the result.  
so for 3-4b =10b +10, add 4b to each side to get
3 = 14b +10
subtract 10 from each side to get -7 = 14b
divide each side by 14 to get -1/2 = b
for 12 +1.5a = 3a, subtract 1.5a from each side to get
12 = 1.5a
divide each side by 1.5 to get 8 = a
You can now do the other one.