Question 147540
Are you trying to factor {{{16y^2+25}}} ? If you are, then it is <font size=4><b>not</b></font> factorable.



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Are you trying to factor {{{16y^2-25}}} ?


{{{16y^2-25}}} Start with the given expression


{{{(4y)^2-25}}} Rewrite {{{16y^2}}} as {{{(4y)^2}}}


{{{(4y)^2-(5)^2}}} Rewrite {{{25}}} as {{{(5)^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=4y}}} and {{{B=5}}}


{{{16y^2-25=(4y+5)(4y-5)}}} Plug in {{{A=4y}}} and {{{B=5}}}


So the expression


{{{16y^2-25}}}


factors to


{{{(4y+5)(4y-5)}}}


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