Question

Find the sum and choose the correct answer.

2n 3 + 4n 2 - 7 and -n 3 - 8n - 2
-n3 + 4n2 - 8n - 9
n3 + 4n2 - 8n - 9
n3 + 4n2 - 8n - 5
n3 - 4n2 -9

Answer 1

Hi

2n³ + 4n² - 7 + (-n³ - 8n - 2) = 2n³ - n³ + 4n² - 8n - 7 - 2

n³ + 4n² - 8n - 9

Answer: n³ + 4n² - 8n - 9

Answer 2

Correct answer is:

n³+4n²-8n-9

Explanation:

We have to find the sum of:

2n³ + 4n² - 7 and -n³ - 8n - 2

On adding both terms:

2n³ + 4n² - 7 + (-n³ - 8n - 2)

= 2n³ - n³ + 4n² - 8n - 7 - 2

= n³+4n²-8n-9

Hence, sum of 2n³ + 4n² - 7 and -n³ - 8n - 2 is:

n³+4n²-8n-9