pls I need help to solve this:
9(y-1)^2-25
I assume you're supposed to factor the expression?
Recall that a^2 - b^2 = (a+b)(a-b)
You have
(3(y-1))^2 - 5^2
= (3(y-1)+5)(3(y-1)-5)
= (3y+2)(3y-8)
9(y-1)^2-25
Recall that a^2 - b^2 = (a+b)(a-b)
You have
(3(y-1))^2 - 5^2
= (3(y-1)+5)(3(y-1)-5)
= (3y+2)(3y-8)