First, let's find the additive inverse of the linear expression within the second set of parentheses. To do so, we can distribute -1 into the second set of parentheses. When we do so, we multiply each term of that linear expression by -1.
Now, let's identify which, if any, terms can be combined. Remember, only like terms — constant terms or terms with the same variable — can be combined.
( 9x - 12)+( -5x+ 7)
In this case, we have two x-terms and two constants. Let's arrange the like terms in columns. Then, let's perform the addition.
9 x -12&
(+) -5 x +7&
4 x -5 &
Therefore, we get the following result.
(9x-12)-(5x-7) = 4x-5
