Bài 1:
`a)(3x+2y)²`
`=(3x)²+2.3x.2y+(2y)²`
`=9x²+12xy+4y²`
`b)(4x²-1)^2`
`=(4x^2)^2-2.4x².1+1²`
`=16x^4-8x²+1`
`c)(x³+2x)²`
`=(x^3)^2+2.x³.2x+(2x)²`
`=x^6+4x^4+4x²`
`d)(2x+1)(2x-1)`
`=(2x)²-1²`
`=4x²-1`
`e)(1-x)(1+x)`
`=1²-x²`
`=1-x`
`f)(5x-2y^2)^2`
`=(5x)²-2.5x.2y²+(2y^2)^2`
`=25x²-20xy²+4y^4`
Bài 2:
`a)(x+3)³`
`=x³+3.x².3+3.x.3²+3³`
`=x³+9x²+27x+27`
`b)(2x-1)³`
`=(2x)³-3.(2x)².1+3.2x.1²-1³`
`=8x³-12x²+6x-1`
`c)(y+3)³`
`=y³+3.y².3+3.y.3²+3³`
`=y³+9y²+27y+27`
`d)(2x+y)³`
`=(2x)³+3.(2x)².y+3.2x.y²+y³`
`=8x³+12x²y+6xy²+y³`
`e)(x²+2)^3`
`=(x^2)^3+3.(x^2)^2 .2+3.x².2²+2³`
`=x^6+6x^4+12x²+8`
`f)(x²-2y)^3`
`=(x^2)^3-3.(x^2)^2 .2y+3.x².(2y)²-(2y)³`
`=x^6-6x^4y+12x²y²-8y³`
