Perform the indicated operations.
-$\left( 3 x ^ { 9 } - 8 x ^ { 8 } + 2 x ^ { 7 } + 7 \right) + \left( 5 x ^ { 9 } - 5 x ^ { 8 } - 9 x ^ { 7 } + 5 \right)$
A) $8 x ^ { 9 } - 13 x ^ { 8 } - 7 x ^ { 7 } + 12$
B) $8 x ^ { 18 } - 13 x ^ { 16 } - 7 x ^ { 14 } + 12$
C) $8 x ^ { 9 } - 13 x ^ { 8 } + 8 x ^ { 7 } - 3$
D) $- 12 x 48 + 12$

Question

Quizplus · Accepted Answer

To solve, add the coefficients of like terms: $3x^9 + 5x^9 = 8x^9$, $-8x^8 - 5x^8 = -13x^8$, $2x^7 - 9x^7 = -7x^7$, and $7 + 5 = 12$.

Perform the Indicated Operations (3x9−8x8+2x7+7)+(5x9−5x8−9x7+5)\left( 3 x ^ { 9 } - 8 x ^ { 8 } + 2 x ^ { 7 } + 7 \right) + \left( 5 x ^ { 9 } - 5 x ^ { 8 } - 9 x ^ { 7 } + 5 \right)(3x9−8x8+2x7+7)+(5x9−5x8−9x7+5)

Perform the Indicated Operations $\left( 3 x ^ { 9 } - 8 x ^ { 8 } + 2 x ^ { 7 } + 7 \right) + \left( 5 x ^ { 9 } - 5 x ^ { 8 } - 9 x ^ { 7 } + 5 \right)$