Meredith Y.
Factoring Trinomials
Welcome to the wonderful world of Factoring (enter unenthusiastic applause here). Here we'll shall be discussing -what else- factoring polynomials.
Say you have something like: 2x-8y. Notice how 2 can be divided from each of them. Now, you'll have something like this: 2(x-4y). Elementary right, good.
Now try a trinomial.
x2-5x-6
Look complicated? Of course not. Just think of it as doing FOIL backwards. Think of the equation as:
x2-5x-6= ( _ _ _ ) (_ _ _)
Notice how x2 doesn't have a coefficient before it. That means that x has just been multiplied by itself - thus the square. So now you have (x_ _ ) (x _ _) . Fascinating isn't it. (enter sarcastic snort here.)
Now look at the last number of the trinomial. This will help you identify the rest of the equation. List out the numbers that are multiples of the last number. For example, here we have 6 so we would list out multiples -you guessed it-6. So we would have: 1,6 and 2,3
So now we come to the middle part. Notice the sign of 5x and you'll see that in the equation its negative. This means that the signs in the equation (x_ _ ) (x _ _) will have one positive and one negative. So we now have (x+ _ ) (x - _).
Now we come to the last part ( enter enthusiastic cheers and applause). All that's left is figuring out which numbers go into the equation. Look at the number -5 -for the moment just forget the x. JUST FOR THE MOMENT! Now look at the multiples that you have found- you know the 1,6 and 2,3. Now find which multiples, when added together, gives you -5. Look at the signs in the equation (x+ _ ) (x - _) and note that one number will be negative (Duh!) and that it will be one of the bigger multiples that will be larger (again another Duh!) So fill in the number. You should have gotten (Heaven willing): (x+1) (x-6).
Above is another way to figure out the equation. By listing out all the multiples and in every situation this gives you every possibility for the equation.
Now remember nothing can supplement a real math lesson from a real math teacher- especially if it's being supplemented by a high school student whose barley doing well in the class anyway.
http://www.mathpower.com/tutorial.htm (This is a link to a tutorial page set up by Professor Freeman. If you scroll down, it provides other information it to the chaotic mess of factoring.)
This furry little marsupial will lead out of this way-ward world of Math.
Courage is resistance to fear, mastery of fear, not absence of fear -Mark Twain (From the website Brainy Quote : http://www.brainyquote.com/)