Question 1010000
It's (x+4)
Synthetic division
-4 ;;; 4;;-21;;-46;;219;;180
====4;;-37+102;;-189;not zero
Alternatively, can do f(-4)=1024+1344-736-876+180, and that does not equal zero.
{{{graph(300,200,-10,10,-50,400,4x^4-21x^3-46x^2+219x+180)}}}