How do you simplify (3a+4b)-(-6a-3b)?

Feb 9, 2015

You first get rid of the brackets (remembering that the minus sign changes all the signs inside the bracket):

$\left(3 a + 4 b\right) - \left(- 6 a - 3 b\right) =$

$= 3 a + 4 b + 6 a + 3 b =$
Now you can add together (or subtract) similar terms (that have the same letters):

$= 3 a + 6 a + 4 b + 3 b = 9 a + 7 b$

hope it helps