Question

How do you simplify `(7t - 8) - ( - 7t - 8)`?

Answer 1

`14t`

Explanation:

We have two kinds of terms: ones that have a variable, `t`, and those that don't. We handle them separately.

Let's first distribute the negative sign on the right side:

`(7t-8)-(-7t-8)`

`7t-8+7t+8`

With the Communative Law, we can rearrange addition and subtraction, so let's group the `t` terms together and the non `t` terms together:

`7t+7t-8+8`

And the Associative Law says I can group different groups together and not change the value of the expression:

`(7t+7t)+(-8+8)`

In the first bracket, we have `7t` and 7 more `t`, for a total of `14t`. In the second bracket, we have a negative 8 and a positive 8, which add to 0. That all gives us:

`14t+0=14t`