Add or subtract.
-$$\left( 5 x ^ { 8 } - 8 x ^ { 3 } + 7 x ^ { 2 } + 6 \right) + \left( 4 x ^ { 7 } + 5 x ^ { 3 } - 9 x \right)$$
A) $9 x ^ { 8 } - 13 x ^ { 3 } + 7 x ^ { 2 } - 9 x + 6$
B) $5 x ^ { 8 } + 4 x ^ { 7 } - 3 x ^ { 3 } + 7 x ^ { 2 } - 9 x + 6$
C) $5 x ^ { 8 } + 4 x ^ { 7 } + 3 x ^ { 3 } + 7 x ^ { 2 } - 9 x + 6$
D) $9 x ^ { 8 } - 3 x ^ { 3 } + 7 x ^ { 2 } - 9 x + 6$

Question

Quizplus · Accepted Answer

When adding polynomials, we simply combine like terms. So, we add the coefficients of each term that has the same degree of x. Using the distributive property, we get:
$$\left( 5 x ^ { 8 } - 8 x ^ { 3 } + 7 x ^ { 2 } + 6 \right) + \left( 4 x ^ { 7 } + 5 x ^ { 3 } - 9 x \right) = 5 x ^ { 8 } + 4 x ^ { 7 } - 3 x ^ { 3 } + 7 x ^ { 2 } - 9 x + 6$$
Therefore, the correct answer is B.

Add or Subtract (5x8−8x3+7x2+6)+(4x7+5x3−9x)\left( 5 x ^ { 8 } - 8 x ^ { 3 } + 7 x ^ { 2 } + 6 \right) + \left( 4 x ^ { 7 } + 5 x ^ { 3 } - 9 x \right)(5x8−8x3+7x2+6)+(4x7+5x3−9x)

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