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.

Respuesta :

Answer:

[tex]12a^2-9a+5[/tex]

Step-by-step explanation:

We are required to evaluate:

[tex](5a^2-6a-4)-(-7a^2+3a-9)[/tex]

First, we open the bracket

[tex]=5a^2-6a-4+7a^2-3a+9[/tex]

Next collect like terms

[tex]=5a^2+7a^2-6a-3a+9-4[/tex]

Simplify your result

[tex]=12a^2-9a+5[/tex]