Question

Find the sum or difference. (3a – 3a^2) + (5 + 8a)

A: a^2 + 11a + 5

B: –3a^2 + 11a + 5

C: 3a^2 + 11a + 5

D: –3a^2 + 11a – 5

Answer 1

Answer: B. -3a^2 + 11a + 5

1.) Remove parentheses.

3a−3a​^2​​ +5+8a

2.) Collect Like Terms.

(3a+8a) - 3a^2+5

3.) Simplify.

11a - 3a^2+5

-3a^2 + 11a + 5

Answer 2

Answer: B = –3a^2 + 11a + 5

For difference, the answer is

-3a^2 -5a -5

Explanation:

(3a – 3a^2) + (5 + 8a)

To find the sum or difference, we will open the brackets.

To look for l the sum, we add

3a – 3a^2 + 5 + 8a

Collecting like terms,

= -3a^2 +8a + 3a +5

= -3a^2 + 11a + 5

Option B is the right answer.

To look for the difference, we subtract.

(3a – 3a^2) - (5 + 8a)

Opening the brackets

3a – 3a^2 - 5 - 8a

Collecting like terms

-3a^2 + 3a -8a -5

= -3a^2 -5a -5

The options available corresponds only to what we got for the sum, so

-3a^2 + 11a + 5 is the answer