Discover a world of knowledge at Westonci.ca, where experts and enthusiasts come together to answer your questions. Connect with professionals on our platform to receive accurate answers to your questions quickly and efficiently. Our platform offers a seamless experience for finding reliable answers from a network of knowledgeable professionals.

x2 - x - 6 =
Simplified. I know the answer is (x+2)(x-3), but I don't understand how the answer was achieved. Can I please get an explanation of this?


Sagot :

[tex]x^2-x-6=(x+2)(x-3)\\\\-x=2x-3x\\-6=2\times(-3)\\\\or\\\\x^2-x-6=x^2+2x-3x-6=x(x+2)-3(x+2)=(x+2)(x-3)[/tex]
AL2006
I had a lot of trouble with this when my algebra class started doing it,
a long time ago.

The key is this:  Look at the -6 at the end.  You have to find two factors
of that number that add up to the -1 in the middle.

Here are the possible factors of -6 :

-1 ... 6
+1 ... -6
-2 ... 3
+2 ... -3

Can you find a pair on the list that adds up to -1 ? 
How about +2 and -3 ?
Their product is -6 and their sum is -1.  That's what you need.

Now set up a couple of binomial factors like this:  (x....) (x....)
and write in the pair of numbers you found:  (x + 2) (x - 3)
That's the factored form of the original expression.