Answer
$=(y-3+5x)(y-3-5x)$.
Work Step by Step
The given expression is
$=y^2-6y+9-25x^2$
Factor each term.
$=y^2-2(y)(3)+3^2-(5x)^2$
Group the terms as a perfect square trinomial and perfect square term.
$=[y^2-2(y)(3)+3^2]-[(5x)^2]$
Use the special formula $A^2-2AB+B^2=(A-B)^2$.
We have $A=y$ and $B=3$
$=(y-3)^2-(5x)^2$
Use the special formula $A^2-B^2=(A+B)(A-B)$.
We have $A=y-3$ and $B=5x$
$=(y-3+5x)(y-3-5x)$.
