How do you factor #x^4+6x^3-36x^2-216x#?
1 Answer
May 22, 2017
Explanation:
#x^4+6x^3-36x^2-216x#
#=x(x^3+6x^2-36x-216)larr" common factor " x#
#"note that when " x=6#
#x^3+6x^2-36x-216=0#
#rArrx=6" is a root and hence " (x-6)" is a factor"#
#rArrx^2(x-6)+12x(x-6)+36(x-6)#
#=(x-6)(x^2+12x+36)#
#=(x-6)(x+6)(x+6)#
#rArrx^4+6x^3-36x^2-216x=x(x-6)(x+6)^2#
