Выполните действия (дроби)

1) 2m^2-n^2/m^3+n^3 - m-n/m^2-mn+n^2

2) 1/x+3 - x^2+18/x^3+27

2m²-n² - m-n = 2m²-n² - m-n =

m³+n³ m²-mn+n² (m+n) (m²-mn+n²) (m²-mn+n²)

=2m²-n² - (m-n) (m+n) = 2m²-n²-m²+n² = m²

(m+n) (m²-mn+n²) m³+n³ m³+n³

2) 1 - х²+18 = 1 - х²+18 = х²-3 х+9-х²-18 = - 3 х-9 =

х+3 х³+27 х+3 (х+3) (х²-3 х+9) (х+3) (х²-3 х+9) (х+3) (х²-3 х+9)

= - 3 (х+3) = - 3 = 3

(х+3) (х²-3 х+9) х²-3 х+9 3 х-х²-9