Question

factor of polynomial

Answer 1

5x(3x-4)
X=0 or x=4/3

Answer 2

1.
$15 {x}^{2} - 20x$
take 5x common
$5x(3x - 4)$

2.
$16 {x}^{2} - 81 {y}^{2}$
${(4x)}^{2} - {(9y)}^{2}$
using identity
$( {a}^{2} - {b}^{2} ) = {a}^{2} + {b}^{2}$
we get
(4x-9y)(4x+9y)