Question 597823

{{{y^2-121z^2}}} Start with the given expression.



{{{(y)^2-(11z)^2}}} Rewrite {{{121z^2}}} as {{{(11z)^2}}}.



Notice how we have a difference of squares {{{A^2-B^2}}} where in this case {{{A=y}}} and {{{B=11z}}}.



So let's use the difference of squares formula {{{A^2-B^2=(A+B)(A-B)}}} to factor the expression:



{{{A^2-B^2=(A+B)(A-B)}}} Start with the difference of squares formula.



{{{(y)^2-(11z)^2=(y+11z)(y-11z)}}} Plug in {{{A=y}}} and {{{B=11z}}}.



So this shows us that {{{y^2-121z^2}}} factors to {{{(y+11z)(y-11z)}}}.



In other words {{{y^2-121z^2=(y+11z)(y-11z)}}}.