Question

7a^2+3a-9−7a 2 +3a−9 minus, 7, a, squared, plus, 3, a, minus, 9 from 5a^2-6a-45a 2 −6a−45, a, squared, minus, 6, a, minus, 4. Your answer should be a polynomial in standard form.

Answer 1

`12a^2-9a+5`

Explanation:

We are required to evaluate:

`(5a^2-6a-4)-(-7a^2+3a-9)`

First, we open the bracket

`=5a^2-6a-4+7a^2-3a+9`

Next collect like terms

`=5a^2+7a^2-6a-3a+9-4`

Simplify your result

`=12a^2-9a+5`