Question

Factor completely: 3x2 − x − 4

(3x − 1)(x + 4)
(3x + 4)(x − 1)
(3x − 2)(x + 2)
(3x − 4)(x + 1)

Answer 1

PLEASE!

Answer 2

did you find the GCF (greatest common factor)?

Answer 3

no i dont understand how to do that

Answer 4

could you walk me through it

Answer 5

okay well its a factoring problem this what you do, hold on

Answer 6

let y= x^2 then think of it as:

y^2-3y-4 then you have:

(y+1)(y-4)

so:

(x^2 +1 ) (x^2 -4)

now keep factoring:

(x^2 +1)(x-2)(x+2)

For high school math you'd stop here but, you can factor it more if you are using imagery numbers...

(x-i)(x+i)(x-2)(x+2)

where i = sqrt(-1)

Hence the expression would have 4 roots when set equal to zero as expected.

Answer 7

does that help?

Answer 8

yes thank you

Answer 9

The factors multiplied will be equal to the coefficient of x^2 and the constant multiplied, in this case 3 and -4, so -12. When added, they will be equal to the coefficient of the x term so -1 in this case. Thus the terms will be (3x − 4)(x + 1).

Answer 10

Sorry that was a little unclear.
3x2 − x − 4 = 3x2 + 3x - 4x -4
=3x(x+1) -4(x+1)
=(3x-4)(x+1)
The factors I was talking about were the coefficients of the x terms.