Question 189941
we are given the expression:

{{{ 4x^4+5x^3+16x^2+20x }}}

we group the first two term together and the last two terms together and find out the common factors of each.

we have:

{{{ (4x^4+5x^3)+ (16x^2+20x) }}}

{{{ x^3 (4x+5)+ 4x(4x+5) }}}

=> {{{ (x^3 + 4x)(4x+5)}}}

we can again take out x as common from x^3 + 4x.
=> {{{ x(x^2 + 4)(4x+5) }}}

so thats our answer.