SOLUTION: Factor completely. 64r^2-121 Thank you!!

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Question 222692: Factor completely. 64r^2-121
Thank you!!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

64r%5E2-121 Start with the given expression.


%288r%29%5E2-121 Rewrite 64r%5E2 as %288r%29%5E2.


%288r%29%5E2-%2811%29%5E2 Rewrite 121 as %2811%29%5E2.


Notice how we have a difference of squares A%5E2-B%5E2 where in this case A=8r and B=11.


So let's use the difference of squares formula A%5E2-B%5E2=%28A%2BB%29%28A-B%29 to factor the expression:


A%5E2-B%5E2=%28A%2BB%29%28A-B%29 Start with the difference of squares formula.


%288r%29%5E2-%2811%29%5E2=%288r%2B11%29%288r-11%29 Plug in A=8r and B=11.


So this shows us that 64r%5E2-121 factors to %288r%2B11%29%288r-11%29.


In other words 64r%5E2-121=%288r%2B11%29%288r-11%29.