simplify (4p+9)(4p-9)?
answer 16p^2-72p-81
answer 16p^2-72p-81
Andrew K
Favorite Answer
I don't know about you, but I think the answer you provided is wrong. If you multiply it all out, you get 16p^2 + 36p - 36p - 81. So simplifying that would be 16p^2 -81
the.dibster
the answer is NOT 16p^2 - 72p -81
it's just 16p^2 -81 (FOIL it, the +and- cancel)
BTW the original thing to simplify are called "conjugates". when you multiply them you get a "difference of squares" which is what you see the answer really is.
Although, some may argue it was already simplified, but 16p^2 -81 is probably what they're looking for
Punkin
Distribute:
16p^2-36p+36p-81
Answer: 16p^2-81
You almost had it! I think you forgot about the negative(-) sign.....You have to remember it next time!
Me
FOIL the answer:
(4p*4p)(4p*-9)(4p*9)(9*-9)
16p^2-36p+36p-81
The two 36p's cancel each other out
16p^2-81
There's your solution