Question

a) \(x^3+x^2-x-1\)

b) \(5x^2-15x-2\left(x-3\right)\)

c) \(25x^2-25+xy-y\)
Giúp mình với ạ

Answer 1

`a)x^3+x^2-x-1=x^2(x+1)-(x+1)=(x+1)(x^2-1)=(x+1)^2 (x-1)`

`b)5x^2-15x-2(x-3)=5x(x-3)-2(x-3)=(x-3)(5x-2)`

`c)25x^2-25+xy-y=25(x^2-1)+y(x-1)=25(x-1)(x+1)+y(x-1)`

                                           `=(x-1)[25(x+1)+y]=(x-1)(25x+25+y)`

Answer 2

a: \(=x^2\left(x+1\right)-\left(x+1\right)=\left(x+1\right)^2\cdot\left(x-1\right)\)

b: =5x(x-3)-2(x-3)=(x-3)(5x-2)

b: \(=25\left(x-1\right)\left(x+1\right)+y\left(x-1\right)=\left(x-1\right)\left(25x+25+y\right)\)