Question

Разложить на множители.
1) (с+b)²-81=
 
2) 5(y+1)²-5(y+1)

3) 3(c+d)-(c+d)³

Answer 1

(c+d-9)(c+d-9)
5(y+1)(y+1)-5(y+1)=5(y+1)(y+1-1)=5y(y+1)
3(c+d)-(c+d)(c+d)=(c+d)(3-c-d)