Question

Find the sum and choose the correct answer.

2n 3 + 4n 2 - 7 and -n 3 + 8n - 9
-n3 - 4n2 - 8n - 16
n3 + 4n2 + 8n - 16
n3 + 4n2 + 8n + 16
3n3 + 4n2 + 8n - 2

Answer 1

B, n to the 3rd power + 4n to the 2nd power +8n -16

Answer 2

Option B (n³ + 4n² + 8n - 16)

Explanation:

In this question we have to add two expressions given

( 2n³ + 4n² - 7 ) and ( -n³ + 8n - 9 )

( 2n³ + 4n² - 7 ) + ( -n³ + 8n - 9 )

Now we group the similar terms

( 2n³ - n³ ) + 4n² - ( 7 + 9 ) 8n

= n³ + 4n² - 16 + 8n

= n³ + 4n² + 8n - 16

Option B (n³ + 4n² + 8n - 16) is the correct answer.