\(Bài1\\ a,=x^2+4x+4\\ b,=x^2-2x+1\\ c,=x^4+2x^2y^2+y^4\\ d,=x^6+4x^3y^2+4y^4\\ e,=x^4-2x^2y^2+y^4\\ f,=x^2-2xy^2+y^4\)
Bài 2:
`a)=(x+2)^2`
`b)=(x-4)^2`
`c)=x^2 - 10`
`d)=(x+1)^2`
`e)=(2x-3)(2x+3)`
`f)=b^2 x^4 -4`
`f)`mờ quá
Bài 3:
`A=(x-y)^2 + (x+y)^2`
`A=[(x-y)+(x+y)][(x-y)-(x+y)]`
`A=(x-y+x+y)(x-y-x-y)`
`A=2x . (-2y)`
`A=-4xy`
`B=(2a+b)^2 -(2a-b)^2`
`B=[(2a+b)-(2a-b)][(2a+b)+(2a-b)]`
`B=(2a+b-2a+b)(2a+b+2a-b)`
`B=2b . 4a`
`B=8ab`
`C=(x+y)^2 - (x-y)^2`
`C=[(x+y)-(x-y)][(x+y)+(x-y)]`
`C=(x+y-x+y)(x+y+x-y)`
`C=2y . 2x`
`C=4xy`
`**` Mấy bài khác làm tương tự :D