Question 282933: The binomial x²-81 is called a _________ of two__________, and will factor in to(______)(_______)? Answer by Monkibat(7) (Show Source):
You can put this solution on YOUR website! The binomial x²-81 is called a _________ of two__________, and will factor in to(______)(_______)?
is called a difference of two squares. The formula is . You can check by foiling (a+b)(a-b). When you foil (a+b)(a-b) you get the -ab and the +ab cancel out. Leaving you .
In the binomial , is a perfect square and so is 81. The square root of is x and the square root of 81 is 9. =, that factors to (x+9)(x-9). So to check you can foil (x+9)(x-9) you get , the -9x and the +9x cancel and you have your original binomial. .
The answer is: The binomial is called a difference of two squares, and will factor in to (x+9)(x-9).
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