Question

how do you factor 5x2 − 2x − 7

Answer 1

plz help!!!!

Answer 2

\[5x^2 -2x-7\]
First, know that the first number -7 and the last number 5 multiply to equal -35. Then find two factors of -35 that add up to equal -2. In this case, -7 and 5 add up easily.
-7 + 5 = -2

Put 5x and -7x in place of the 2x.
5x^2 + 5x - 7x -7

Group the first 2 terms and the second terms separately like this
(5x^2 + 5x) + (-7x - 7)

Then take out any common factors from both groups. Those are 5x and -7
5x(x + 1) - 7(x+1)

Then group the common factors 5x and -7 you took out into one group. Also, since there are two (x+1)'s, make the x+1 one group like this.
(5x-7) (x+1)

You can check your work by multiplying everything back the way it was and seeing if it is the same as it was in the beginning.

5x^2 + 5x - 7x - 7
5x^2 - 2x - 7

I hope I explained it well enough. Some people do it a different way but this is how I do it.

Answer 3

thank you!

Answer 4

Your welcome :)