SOLUTION: Question #107885 example 1 in your list: 6x^2 - xy - 5y^2. I need to see steps so that I understand how this was done to repeat it on my other problems.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Question #107885 example 1 in your list: 6x^2 - xy - 5y^2. I need to see steps so that I understand how this was done to repeat it on my other problems.      Log On


   



Question 108829: Question #107885 example 1 in your list: 6x^2 - xy - 5y^2. I need to see steps so that I understand how this was done to repeat it on my other problems.
Found 2 solutions by stanbon, checkley71:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
6x^2 - xy - 5y^2
Using the AC Method:
You need to think of two numbers whose product is AC = 6*-5=-30
and whose sum is B=-1
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The numbers are -6 and 5
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Rewrite the problem substituting -6+5 for -1
6x^2 -6xy+5xy -5y^2
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Factor and 1st two terms and the last two terms separately:
6x(x-y) + 5y(x-y)
Factor again:
(x-y)(6x+5y)
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Cheers,
Stan H.

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
6X^2-XY-5Y^2
YOU NEED TO FIND FACTORS OF 6 & 5 THAT WHEN MULTIPLIED & THEN ADDED =-1.
FACTORS ARE 1&6, -1&-6, 2&3, -2&-3 FOR 6
FACTOPRS ARE -1&5, 1&-5 FOR -5
TO FIND THE CORRECT COMBINATION MAKE UP A TABLE OF THE PRODUCTS & THE SUMS TO EQUAL -1.
6*-1+5*1=-6+5=-1 IS THE ONLY COMBINATION TO PASS THE TEST.
(6X+5Y)(X-Y)