To simplify (4a+3b-6) + (2a-b+4) - (-3a-2b) you have to group all the terms with ‘a’, ‘b’ and all terms without a variable in them.
To do this let's start with all terms that have an ‘a’ in them. If we look at the equation we see ‘+4a’, ‘+2a’ and ‘-(-3a)’. This will come down to 4a+2a-(-3a). Since minus times a minus equals a positive, the simplified a term will become: 4a+2a+3a = 9a
Now we do the same for all terms with the ‘b’. We see ‘3b’, ‘-b’ and ‘-(-2b)’. This is equal to 3b-b+2b. This means that all terms with ‘b’ simplify to 4b.
Now we group all terms without a variable. Here we see ‘-6’ and ‘+4’. This is equal to -6+4 which results in -2.
Now on to the last step! Combining our results, in the form all ‘a’ terms + all ‘b’ terms + all terms without a variable. This results in:
9a + 4b -2
I hope this helped!