$\left(6 x^{8}-7 x^{6}+5 x^{2}+9\right)+\left(6 x^{7}+3 x^{6}-5 x\right)$
A) $6 x^{8}+6 x^{7}-4 x^{6}+5 x^{2}-5 x+9$
B) $12 x^{8}-4 x^{6}+5 x^{2}-5 x+9$
C) $12 x^{8}-10 x^{6}+5 x^{2}-5 x+9$
D) $6 x^{8}+6 x^{7}+4 x^{6}+5 x^{2}-5 x+9$

Question

Quizplus · Accepted Answer

To find the sum, combine like terms: $6x^8$ remains unchanged, $6x^7$ is added without a counterpart, $-7x^6 + 3x^6 = -4x^6$, $5x^2$ remains unchanged, $-5x$ is added without a counterpart, and $9$ remains unchanged.

(6x8−7x6+5x2+9)+(6x7+3x6−5x)\left(6 x^{8}-7 x^{6}+5 x^{2}+9\right)+\left(6 x^{7}+3 x^{6}-5 x\right)(6x8−7x6+5x2+9)+(6x7+3x6−5x) A) 6x8+6x7−4x6+5x2−5x+96 x^{8}+6 x^{7}-4 x^{6}+5 x^{2}-5 x+96x8+6x7−4x6+5x2−5x+9

$\left(6 x^{8}-7 x^{6}+5 x^{2}+9\right)+\left(6 x^{7}+3 x^{6}-5 x\right)$ A) $6 x^{8}+6 x^{7}-4 x^{6}+5 x^{2}-5 x+9$