Question

select the correct answer. what is the simplified form of this expression? (-3x^2 + 2x - 4)+(4x^2 + 5x + 9) 7x^2 + 7x + 5 x^2 + 11x + 1 x^2 + 7x + 5 x^2 + 7x + 13

Explanation:

Step1: Remove parentheses

$(-3x^{2}+2x - 4)+(4x^{2}+5x + 9)=-3x^{2}+2x - 4+4x^{2}+5x + 9$

Step2: Combine like - terms for $x^{2}$ terms

$-3x^{2}+4x^{2}=(-3 + 4)x^{2}=x^{2}$

Step3: Combine like - terms for $x$ terms

$2x+5x=(2 + 5)x=7x$

Step4: Combine constant terms

$-4 + 9=5$

Step5: Write the simplified expression

$x^{2}+7x + 5$

Answer:

$x^{2}+7x + 5$ (corresponding to the third option in the multiple - choice list)