Đáp án+Giải thích các bước giải:
`f) 36y^2-9x^2`
`=(6y)^2-(3x)^2`
`=(6y-3x)(6y+3x)`
`g) (2+3x)^2`
`=2^2+2.2.3x+(3x)^2`
`=4+12x+9x^2`
`h) (3x-2y)^2`
`=(3x)^2-2.3x.2y+(2y)^2`
`=9x^2-12xy+4y^2`
`i) (5x+1)^3`
`=(5x)^3+3.(5x)^2 .1+3.5x.1^2+1^3`
`=125^3+75x^2+15x+1`
`j) `Sửa đề:
` (2x-4y)^3`
`=(2x)^3-3.(2x)^2 .4y+3.2x .(4y)^2-(4y)^3`
`=8x^3-48x^2y+96xy^2-64y^3`