SOLUTION: I am confused about simplfying by removing factors of one when a lot of letters are used, for example: z^2-12z+32/z^2+z-20 Help please!

Question 257440: I am confused about simplfying by removing factors of one when a lot of letters are used, for example:
z^2-12z+32/z^2+z-20
Help please!
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
z^2-12z+32/z^2+z-20
Factor the NUM and DEN
= (z-8)*(z-4)/(z+5)*(z-4)
Both NUM and DEN have (z-4), so cancel them.
= (z-8)/(z+5)
-------------
I don't know what "factors of one" means. Dividing by one doesn't change anything.

RELATED QUESTIONS
simplify by removing factors of 1... (answered by Gogonati)

simplify by removing factors of 1.... (answered by jim_thompson5910)

I can't solve this problem z^2-49/7-z for removing factors of... (answered by galactus)

sikplify by removing factors of 1... (answered by benni1013)

Simplify by removing factors of 1 z^2-13z+36 /... (answered by checkley77)

Simplify by removing factors of 1.... (answered by checkley77)

simplify by removing factors of 1... (answered by dabanfield)

Simplify by removing factors of 1 (z^2-64)/(8-z) the simplified form is (answered by user_dude2008)

Please help solve the following. Please show how you came up with the answer so I can see (answered by Alan3354)