Question

Answer 1

Bài `3.3`

`a, A=16x^2-1`

`=(4x)^2-1^2`

`=(4x-1)(4x+1)`

`b, B = 125 + y^3`

`= 5^3+y^3`

`= (5+y)(5^2-5y+y^2)`

`= (5+y)(25-5y+y^2)`

`c, C=27x^3-y^3`

`= (3x)^3 - y^3`

`= (3x-y)(9x^2 + 3xy  + y^2)`

`d, D=  125-27x^3`

`= 5^3- (3x)^3`

`= (5 - 3x)(25 + 15x+ 9x^2)`

 

Answer 2

Bài `3.4`

`a, A= x^2+4x+4`

`=x^2 + 2 . x . 2 + 2^2`

`= (x+2)^2`

`b, B = x^2-16`

`= x^2-4^2`

`=(x-4)(x+4)`

`c, C = a^3-27`

`=a^3-3^3`

`=(a-3)(a^2+3a+9)`

`d, D = y^3 + 3y^2+3y+1`

`= (y+1)^3`