Заложите на множители: 1) a³+8b³+a²-2ab+4b² 2) y²-x²-6x-9 3) (y+5)²-16c² с решением.

1) a³+8b³+a²-2ab+4b² = ( a³+(2b)³)+(a²-2ab+(2b)²) =
 
= (a+2b)(a²-2ab+(2b)²)+ (a²-2ab+(2b)²) =(a²-2ab+(2b)²) *(a+2b+1)

2) y²-x²-6x-9 =2) y²-(x²+6x+3²) = y²-(x+3)²=(y-x-3)*(y+x+3)

3) (y+5)²-16c²=(y+5-4c)*(y+5+4c)