Question

find the sum and choose the correct answer. 2n^3+4n^2-7 and -n^3+8n-9.

A) -n^3-4^2-8n-16

B) n^3+4n^2+8n+16

C) n^3+4n^2+8n-16

D) 3 n^3+4n^4+8n-2

Answer 1

Answer:

C) $n^3+4n^2+8n-16$

Step-by-step explanation:

$2n^3+4n^2-7+(-n^3)+8n-9=\\n^3+4n^2-7+8n-9=\\n^3+4n^2+8n-9-7=\\n^3+4n^2+8n-16$

(Just combine like terms)

Only C) $n^3+4n^2+8n-16$ fits our answer.

Answer 2

Answer:

${n}^{3} + 4 {n}^{2} + 8n - 16$

Option C is the right option

Solution,

$2 {n}^{3} + 4 {n}^{2} - 7 + ( - {n}^{3} + 8n - 9) \\ = 2 {n}^{3} + 4 {n}^{2} - 7 - {n}^{3} + 8n - 9$

combine like terms

$2 {n}^{3} - {n}^{3} + 4 {n}^{2} + 8n - 7 - 9 \\simplify \\ = {n}^{3} + 4 {n}^{2} + 8n - 16$

hope this helps...

Good luck on your assignment..