## Algebra 2 Common Core

$$(y-5)^{2}$$
Factor $$y^{2}−10y+25.$$ Find numbers that are factors of $25$ and sum to $-10$: $$(-5)(-5)=25;\space -5-5=-10.$$ The polynomial is a product of two binomials: $$y^{2}−10y+25=(y-5)(y-5)=(y-5)^{2}.$$