[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]
Let's solve ~
[tex]\qquad \tt \dashrightarrow \:(3 {x}^{5} \times 2xy) - ( {x}^{2} y \times 4 {x}^{4} )[/tex]
[tex]\qquad \tt \dashrightarrow \:6 {x}^{6} y - 4 {x}^{6} y[/tex]
[tex]\qquad \tt \dashrightarrow \:2 {x}^{6} y[/tex]