Помогите срочноо плиз

Ответ:

Объяснение:

- a² - ab - b² =

= - - - =

= =

=  =

=

5x(3-y)-9+3y= 5x·3 + 5x·(-y) - 9 +3y = 15x-5xy-9 + 3y = (15x-5xy) +(9-3y) =

= 5x(3-y) + 3(3-y) = (5x+3)(3-y)

a³-5a²-a+5= (a³-a) - (5a²-5) = a(a²-1) - 5(a²-1) = (a-5)(a²-1) = (a-5)(a-1)(a+1)