Question

"Molly had (4x + 10) dollars. Ron has (-5x + 20) dollars. How much money do they have all together?"

For this part I got -x + 30 dollars, but the problem comes when I see the next part:

"How much more money does Molly have than Ron?"

Now how to I calculate that?

Answer 1

subtract them, just like you added:

4x + 10 - (-5x +20)

The minus turns (-5x + 20) into the opposite, or 5x - 20

4x + 10 + 5x - 20

9x - 10

Answer 2

-1x+30