completely factor: 10y^2 -90
10(y^2 -9)
What you have in parentheses is the difference of two squares.
You should know how to factor that again.
If you don't know how, http://regentsprep.org/REgents/math/ALGEBRA/AV6/Lfactps.htm
What you have in parentheses is the difference of two squares.
You should know how to factor that again.
If you don't know how, http://regentsprep.org/REgents/math/ALGEBRA/AV6/Lfactps.htm