SOLUTION: Completely factor the following expression:y^2-121z^2 show all work please

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Question 597823: Completely factor the following expression:y^2-121z^2
show all work please
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

y%5E2-121z%5E2 Start with the given expression.


%28y%29%5E2-%2811z%29%5E2 Rewrite 121z%5E2 as %2811z%29%5E2.


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


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.


%28y%29%5E2-%2811z%29%5E2=%28y%2B11z%29%28y-11z%29 Plug in A=y and B=11z.


So this shows us that y%5E2-121z%5E2 factors to %28y%2B11z%29%28y-11z%29.


In other words y%5E2-121z%5E2=%28y%2B11z%29%28y-11z%29.