Question

Simplify:
(9 - 5t)(5t - 9)

A)-25t^2+90t-81 B)25t^2+90t-81
C)-25t^2+81 D)-25t^2-81

I've tried this 3 times and got the same answer every time that my teacher said was wrong, help?

Answer 1

use FOIL

Answer 2

i did

Answer 3

(9 - 5t)(5t - 9)

use foil

45t + 81 - 25t^2 + 45t

Combine like terms:

-25t^2 + 90t + 81

Answer 4

oops - 81

Answer 5

(9)(5t) = 45t
(9)(-9) = -81
(-5t)(5t) = -25t^2
(-5t)(-9) = 45t

Answer 6

so you have -25t^2 + 90t -81

Answer 7

that's where i messed up i forgot to switch one of the 45t to positive so it kept coming up as canceling each other out

thank you !! ^.^ <3

Answer 8

yw :)