a) (x2 + 2xy + y2) : (x + y)
ta có: x2 + 2xy + y2 = (x + y)2
Nên: (x2 + 2xy + y2) : (x + y)
= (x + y)2 : (x + y)
= (x + y)
b) (125x3 + 1) : (5x + 1)
ta có: 125x3 + 1 = (5x + 1)(25x2 – 5x + 1)
Nên: (125x3 + 1) : (5x + 1)
= (5x + 1)(25x2 – 5x + 1): (5x + 1)
= 25x2 – 5x + 1
c) (x2 – 2xy + y2) : (y – x)
Ta có: x2 – 2xy + y2 = (x – y)2 = (y – x)2
Nên: (x2 – 2xy + y2) : (y – x)
= (y – x)2 : (y – x)
= y - x