Answer
$25-y^2$
Work Step by Step
$Multiply$ $the$ $algebraic$ $expressions$ $using$ $a$ $Special$ $Product$ $Formula$ $and$ $simplify:$
$(5-y)(5+y)$
Use the Sum and Difference of Same Terms Product Formula: $(A+B)(A-B) = A^2-B^2$
$(5-y)(5+y) = 5^2-y^2$
$=25-y^2$