3a+4b-(-6a-3b)

I will solve a similar question for you

4b - 9a - (-7a + 6b)

First we rewrite the minus sign before the brackets

4b - 9a + (-1(-7a + 6b))

Now we expand out the innermost brackets

4b - 9a + (7a - 6b)

Now we can eliminate the other brackets

4b - 9a + 7a - 6b

Grouping like terms:

(4b - 6b) + (7a -9a)

And now we solve the terms in brackets:

-2b + (-2a)

And expand

-2b - 2a

Now you have a go at yours and let me know what answer you get.

9a 7b

9a + 7b yes you're right! :)