Question

Can someone double check my work?

Simplify the following expression: (5x2 + 3x + 4) − (2x2 − 6x + 3). If the final answer is written in the form Ax2 + Bx + C, what is the value of B?

I got 3x^2 - 3x + 7,

so Bx = -3x??

Answer 1

When you distribute, you need to distribute that negative to EVERY term inside the second parenthesis.

Answer 2

So

(5x^2 + 3x + 4) − (2x^2 − 6x + 3)

becomes

5x^2 + 3x + 4 - 2x^2 + 6x - 3

Notice how it's +6x and NOT -6x

Answer 3

so combine the terms now?

Answer 4

yes

Answer 5

tell me what you get

Answer 6

is the answer 9x?

Answer 7

5x^2 - 2x^2 = 3x^2

3x + 6x = 9x

4 - 3 = 1


So the simplified expression is 3x^2 + 9x + 1


It's in the form Ax^2 + Bx + C


So we can see that Bx = 9x, which means B = 9

Answer 8

thank you! (:

Answer 9

you're welcome