Ответ:

[tex]2 {m}^{2} ( - 3 {n}^{2} ) + 5 {n}^{2} m - 6m {n}^{2} + 6 {m}^{2} {m}^{2} = - 6 {m}^{2} {n}^{2} + 5 {n}^{2} m - 6m {n}^{2} + 6 {m}^{2} {n}^{2} = 5 {n}^{2} m - 6m {n}^{2} [/tex]

Якщо m=-0,5; n=14, то

[tex]5 {n}^{2} m - 6m {n}^{2} =( 5 \times {14}^{2} \times ( - 0.5) ) - (6 \times ( - 0.5 ) \times {14}^{2} ) = - 490 - 588 = - 1078[/tex]