SOLUTION: Factor: 3x squared-19X-40

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Question 215465: Factor: 3x squared-19X-40
Found 3 solutions by vleith, stanbon, drj:
Answer by vleith(2983) About Me  (Show Source):
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Factor: 3x squared-19X-40
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3x^2 - 19x - 40
(x-8)(3x+5)
====================
Cheers,
Stan H.

Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
Factor: 3x%5E2-19x-40

3x%5E2-19x-40

Step 1. Need to find two integers m and n where the product is mn=3*(-40)=-120 and their sum m+n=-19.

Step 2. After several tries, the numbers are -24 and 5.

Step 3. Substitute -19x=-24x%2B5x into 3x%5E2-19x-40 and group terms as follows:

%283x%5E2-24x%29%2B%285x-40%29

Step 4. Factor the first and second group with parenthesis.

%283x%5E2-24x%29%2B%285x-40%29=3x%28x-8%29%2B5%28x-8%29

Step 5. Now factor out x-8 in both groups since it's a common factor.

%283x%5E2-24x%29%2B%285x-40%29=%28x-8%29%283x%2B5%29

Step 6. ANSWER: 3x%5E2-19x-40=%28x-8%29%283x%2B5%29

I hope the above steps were helpful.

For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

Good luck in your studies!

Respectfully,
Dr J