SOLUTION: Factor: y2 – 64 A) (y – 8)(y + 8) B) (y – 8)2 C) (8 – y)(8 + y) D) The expression is prime.

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Question 140006: Factor: y2 – 64
A) (y – 8)(y + 8)
B) (y – 8)2
C) (8 – y)(8 + y)
D) The expression is prime.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
y%5E2-64 Start with the given expression

%28y%29%5E2-64 Rewrite y%5E2 as %28y%29%5E2

%28y%29%5E2-%288%29%5E2 Rewrite 64 as %288%29%5E2


Now use the difference of squares. Remember, the difference of squares formula is A%5E2-B%5E2=%28A%2BB%29%28A-B%29 where in this case A=y and B=8

y%5E2-64=%28y%2B8%29%28y-8%29 Plug in A=y and B=8

So the expression

y%5E2-64

factors to

%28y%2B8%29%28y-8%29

Notice that if you foil the factored expression, you get the original expression. This verifies our answer.