Simplify the following 2a + 3b + 4a - 7b

Answer:2a

We add 2 and 3 and we get 5 then we do 4-7=-3. Then we do 5-3=2 and we add a. (we only add all a's when we multiply)

And the answer is 2a

6a - 4b

You would take 2a and add 4a to it which will give you 6a. Then you will take - 7b and add 3b to it. I usually just subtract when the bigger number is a negative. Once you do that though you will get - 4b. Finally your answer will be 6a - 7b