Answers

2014-07-11T21:27:37+08:00
(x+5) (x-5)
=x²-5x+5x-25
=x²-25
1 5 1
2014-07-11T21:57:07+08:00
(x+5) (x-5)
since the given are conjugates, multiply the first terms 
(x) (x)
  = x²
and, multiply also the last terms
(5) (-5)
 = -25

the product is x²-25
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