Question 733807
r^2+3r-10 
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The AC Method:
A*C: 2*-5 = -10 
B :: 2+-5 = 3 
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Use reverse FOIL to get:
r^2 + (2r-5r) -10 
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Factor each pair as follows:
(r^2+2r) + (-5r-10)
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r(r+2)-5(r+2)
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= (r+2)(r-5)
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Cheers,
Stan H.
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