8x^2-14x+3?

Question

i have to unfoil. i got (4x-7) (2x+2) wrong?

Answer 1

You can see thats wrong, because the two constant terms multiply to -14 instead of 3.
Its going to either be (8x+?)(x+?) or (4x+?)(2x+?).
Lets try the second one:
(4x+a)(2x+b). You need a and b to multiply to 3, while 4*b + 2*a = -14. Trying a couple of different possibilities shows that b = -3 and a = -1 works.
So (4x-1)(2x-3).

Answer 2

You did well to get 4x and 2x as the factors of 8x^2.
But don't forget, it could also be x and 8x.

Where you went wrong, was in getting the 7 and the 2.
These are factors of the 14 in -14x, but that's not what
you want. What you want are the factors of the constant
term, 3, which are 1 and 3.
The rule is that you have to factor the term in x^2 and
the constant, not the term in x.

So the factors of 8x^2 are 4x and 2x or, x and 8x.
And the factors of the constant are 1 and 3.

Next, because the 3 is positive and the 14x is
negative, the 2 signs will be both negative.
Two negative constants multiplied together
give a positive constant and the two negative
x-terms that will result, will give a negative
x-term when they added to each other.

Putting all that together in as many ways as
possible, gives you these 4 combinations :

(4x - 3)(2x - 1)
(4x - 1)(2x - 3)
(x - 3)(8x - 1)
(x - 1)(8x - 3)

So now you have to find which one has the
x-terms that add to -14x.

(4x - 3)(2x - 1) gives : -4x - 6x = -10x (no good)
(4x - 1)(2x - 3) gives : -12x - 2x = -14x (this is it)
(x - 3)(8x - 1) gives : -x - 24x = -25x (no good)
(x - 1)(8x - 3) gives : -3x - 8x = -11x (no good)

Answer 3

x= 1/4, 3/2

Answer 4

Yes, that answer is wrong. Here's the right answer:
(4x-1)(2x-3)

Answer 5

Yes, (4x-7)(2x+2) is 8x^2-6x-14 not 8x^2-14x+3

Answer 6

8x² - 14x + 3
= 8x² -12x - 2x + 3
= 2x(4x - 1) - 3(4x - 1)
= (4x - 1)(2x - 3)

Answer 7

<4x-1><2x-3>

Answer 8

8x**2-14x+3
= 8x**2-12x-2x+3
= 4x(2x-3)-1(2x-3)
= (2x-3)(4x-1)Ans.
So you are wrong.

Answer 9

Use the Quadratic Formula!

Answer 10

(4x - 1) (2x - 3)