SOLUTION: Factor completely: x^2 - 2x + y^2 + 2y - 2xy

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Question 371648: Factor completely: x^2 - 2x + y^2 + 2y - 2xy - 15
Found 2 solutions by mananth, stanbon:
Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website!
x^2 - 2x + y^2 + 2y - 2xy - 15
...
re=write the expression
x^2-2xy+y^2-2x+2y-15
(x-y)^2-2(x-y)-15
substitue x-y =a
a^2-2a-15
a^2-5a+3a-15
a(a-5)+3(a-5)
(a-5)(a+3)
resubstitute the value of a
(x-y-5)(x-y+3)
...
m.ananth@hotmail.ca

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
Factor completely:
x^2 - 2x + y^2 + 2y - 2xy - 15
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Rearrange:
x^2-2xy+y^2 -2(x-y) - 15
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(x-y)^2 -2(x-y) - 15
This is a quadratic with variable (x-y)
Factor:
[(x-y)-5][(x-y)+3]
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Cheers,
Stan H.

SOLUTION: Factor completely: x^2 - 2x + y^2 + 2y - 2xy - 15