Đáp án+Giải thích các bước giải:
$1)5x^2+10xy+5y^2\\=5.(x^2+2xy+y^2)\\=5.(x+y)^2\\2)x^4-2x^3+x^2\\=x^2.(x^2-2x+1)\\=x^2.(x-1)^2$
$3)x^3-64x\\=x(x^2-8^2)\\=x.(x-8)(x+8)\\4)8x^2y-18y\\=2y((2x)^2-3^2)\\=2y(2x-3)(2x+3)$
$5)36x^2-(x+9)^2\\=(6x)^2-(x+9)^2\\=(6x-x-9)(6x+x+9)\\=(5x-9)(7x+9)\\6)5x^2+10x+5-5y^2\\=5.(x^2+2x+1)-5y^2\\=5.(x+1)^2-5y^2\\=5.[(x+1)^2-y^2]\\=5.[(x+1-y)(x+1+y)]$
