Question

How do you simplify `(a + b)(a - 2b)`?

Answer 1

When you say simplify I'm going to take it as expand since factoring an expression is sometimes a way of simplifying it.
The answer will be `a^2 -2b^2-ab`

Explanation:

You simply multiply out each factor.

So you start by multiplying the `a` in `(a+b)` to each term in `(a-2b)`.
You will get `a^2-2ab` as the first portion of the answer.

So now you will do the same with the `b` in `(a+b)`.
Then you get `-2b^2+ab`.

Now you add `a^2-2ab` and `-2b^2+ab` to get `a^2 -2b^2-ab` .