Question

1. 8x^2 + 10x - 9
2. 3x^4 - 14x^2 - 9
3. 4x^2 + 5x - 9
4. 8x^2 + 10x - 18

Answer 1

4.

Explanation:

(x^2 + 7x - 9) + (3x^2 - 2x) + (x^2 + 7x - 9) + (3x^2 - 2x)

x^2 + 7x - 9 + 3x^2 - 2x + x^2 + 7x - 9 + 3x^2 - 2x

Rearranging order:

3x^2 + 3x^2 + x^2 + x^2 + 7x + 7x - 2x - 2x - 9 - 9

Combine like terms

8x^2 + 10x - 18

Answer 2

Perimeter is all sides added up
2(3x^2-2x) + 2(x^2+7x-9)
= 6x^2 - 4x + 2x^2 +14x - 18
Simplify
8x^2 + 10x - 18
It would be number 4