Question

Descompuneti in factori 
(y-3)³ + (y+1)³

Answer 1

a ³ + b ³ = (a + b)(a ² - ab + b ² )

a³=(y-3)³ și b³=(y+1)³

(y-3)³ + (y+1)³ = (y-3+y+1)·[(y-3)² - (y-3)·(y+1) +(y+1)²] = (2y-2)·[(y² -6y+9) - (y² +y-3y-3)+y²+2y+1]= 2(y-1)·(y² -6y+9 - y² +2y +3+y²+2y+1) =2·(y-1)·(y² -2y +13)

Answer 2

(y-3)³ + (y+1)³ = (y-3+y+1)[(y-3)² - (y-3)(y+1) +(y+1)²] =
= 2(y-1)(y² -6y+9 - y² +2y +3+y² +2y+1) = 2(y-1)(y² -2y +13)