How do you factor #9x^3-36x^2-25x+100#?

1 Answer
Sep 1, 2016

Answer:

#(x-4)(3x+5)(3x-5)#

Explanation:

There are 4 terms, but there is no common factor in all the terms,
Pair the terms to make common factors, make sure there is a + sign between the pairs.

#9x^3 -36x^2 -25x+100 " = "(9x^3 -36x^2)+ ( -25x+100) #

=#9x^2(x-4) color(magenta)(+) 25(color(blue)(-x+4))#

=#9x^2(x-4) color(magenta)(-) 25(color(blue)(x-4)) larr" "# note sign change.

=#(x-4)(9x^2 -25)#

=#(x-4)(3x+5)(3x-5)#