Question

Add: (4 – 3n – 5n2) + (–2 + n – 3n2)

A. 2 – 4n – 8n2

B. 2 – 2n – 8n2

C. –2 – 2n – 8n2

D. –2 – 4n – 8n2

I believe this one is B.

Answer 1

Add: (2x – y – 2z – 6) + (–6x + 4y + 3z + 8)

A. –4x + 3y + z + 2

B. 4x – 3y – z + 2

C. –4x + 3y –z – 2

D. 4x – 3y + z + 2

I believe this one is A.

Answer 2

Let's do the first problem first.

Answer 3

Okay.

Answer 4

So for number 1 here are the steps I did...

Answer 5

4 + -2 = 2

-3n + n = -2n

-5n^2 - 3n^2 = -8n^2

Answer 6

Correct.

Answer 7

And then I put them all together so equal 2 - 2n - 8n^2

Answer 8

Okay great!

Answer 9

I prefer to keep rewriting what the problem is, so I don't forget any terms.
This is how I'd do it.

Answer 10

That makes sense. Is #2 correct?

Answer 11

@imqwerty

Answer 12

\((4 - 3n - 5n2) + (-2 + n-3n^2) \)

Since the two trinomials are being added, the parentheses can be dropped.

\(= 4 - 3n - 5n^2 + (–2) + n - 3n^2 \)

Now we can place like terms together.

\(= 4 + (-2) - 3n + n - 5n^2 - 3n^2 \)

\(= 2 - 2n - 8n^2\)

Answer 13

Ok. Let's look at 2.

Answer 14

Oh that's a smart way of doing it. I never thought about that.

Answer 15

\( (2x - y - 2z - 6) + (-6x + 4y + 3z + 8)\)

Same idea here. We are adding polynomials, so we can drop both sets of parentheses.

\(= 2x - y - 2z - 6 + (-6x) + 4y + 3z + 8\)

Answer 16

Now we move the like terms together:

\(= 2x + (-6x) - y + 4y - 2z + 3z - 6 + 8\)

Now we combine each set of like terms:

\(=-4x + 3y + z + 2\)

Answer 17

You are correct again.

Answer 18

Oh great. Thanks for helping. I only have a few more left if you don't mind. You are a lifesavor!