Answer
$16y^2-25$
Work Step by Step
RECALL:
$(a+b)(a-b)=a^2-b^2$
Use the formula above to have:
$(4y+5)(4y-5)
\\=(4y)^2 - 5^2
\\=16y^2-25$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.