Now, let's note that adding 0 to an expression does not change the value of the expression. For this reason, we can rewrite our expression as a difference of two linear expression. Let's do it!
(5x - 15) -x = (5x - 15)-(x+ 0)
Next, we will calculate this difference. 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.
( 5x - 15)+( - x+ 0)
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.
5 x -15&
(+) - x +0&
4 x - 15&
Therefore, we get the following result.
5(x-3)-x = 4x-15
