Представьте в виде многочлена выражение 1) ( 0,5x + 4y ) ( 0,5x − 4y ) Выполните...

1.1)
$(0.5x + 4y)(0.5x - 4y) = \\ = (0.5x)^{2} - (4y)^{2} = \\ = 0.25 {x}^{2} - 16 {y}^{2}$
2.1)
$(0.9 {m}^{3} + 7 {n}^{3} )(0.9 {m}^{3} - 7 {n}^{3} ) = \\ = (0.9 {m}^{3} )^{2} - (7 {n}^{3})^{2} = \\ = 0.81 {m}^{6} - 49 {n}^{6}$
2.2)
$(7m + 0.8)(7m - 0.8) = \\ = (7m)^{2} - {0.8}^{2} = \\ = 49 {m}^{2} - 0.64$