Question 140006
{{{y^2-64}}} Start with the given expression


{{{(y)^2-64}}} Rewrite {{{y^2}}} as {{{(y)^2}}}


{{{(y)^2-(8)^2}}} Rewrite {{{64}}} as {{{(8)^2}}}



Now use the difference of squares. Remember, the difference of squares formula is {{{A^2-B^2=(A+B)(A-B)}}} where in this case {{{A=y}}} and {{{B=8}}}


{{{y^2-64=(y+8)(y-8)}}} Plug in {{{A=y}}} and {{{B=8}}}


So the expression


{{{y^2-64}}}


factors to


{{{(y+8)(y-8)}}}


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