Can you please help me factor this?

Question

2x^2-x-28

Thank you guys.

Answer 1

2x^2 - x - 28

(2x + 7)(x - 4) <===

Answer 2

rewrite as

x^2-.5x=14

Complete the square

x^2-.5x+(.5/2)^2=14 +(.5/2)^2

X^2-.5x+(1/4)^2 = 14 +(1/4)^2=(224+1)/16

(x-1/4)^2 =225/16

x-1/4 =+ - 15/4

x(1) = 4

x(2) = -14/4= -7/2

(x+7/2)(x-4)=0

(2x+7)(x-4)= 2x^2 - x -28

Answer 3

(2x - 7) (x + 4) is wrong.

Yes, please check with FOIL:

That first guy's answer gives you 2x^x+x-28, and not 2x^2-x-28.

Moonrose got it right

Answer 4

2x^2 -x -28

(2x - 7) (x + 4)

Check with FOIL:

2x (x) = 2x^2

2x(4) = 8x

-7(x) = -7x

-7(4) = -28

2x^2 + 8x - 7x - 28 = 2x^2 + x - 28