PLEASE HELP!

Explain, in complete sentences, how you would completely factor 20x2 – 28x – 48 by using the grouping method. How would you check your factors for accuracy?

Question

PLEASE HELP!

Explain, in complete sentences, how you would completely factor 20x2 – 28x – 48 by using the grouping method. How would you check your factors for accuracy?

anonymous · Answer

Group your terms together that you can factor.  Then factor what is left.

hero · Answer

First factor what's common to all three terms. 4 is common to all three terms so:
4(5x^2 - 7x - 12)

Next find two numbers m and n in the following manner

$m \times n = -60$
$m + n = -7$

Which if you think about it, you'll realize that m = -12 n = 5

anonymous · Answer

Factor out the GCF of 4. 4(5x2-7x-12)
Do some of the addition and subtraction to get 5x2+5x-12x-12
That's all I got. :/

hero · Answer

Don't forget to leave the 4 in front during the factoring process:

$4(5x^2 + 5x - 12x - 12)$

Then factor by grouping inside the parentheses:
$4(5x(x + 1) - 12(x + 1))$
$4((x + 1)(5x - 12))$
$4(x+1)(5x - 12)$

hero · Answer

Now you'll be able to multiply that out to get back to the original expression.

anonymous · Answer

Umm....

hero · Answer

If you have a question or are confused you should probably state what it is you're confused about.