Rút gọn biểu thức:
(x-2)^2 + x(x^2+x+1)-x(x-2)(x+2)
(2x +3)^2+(2x-3)^2 -2(2x+3)(2x-3)
x(x+4)(x-4) -(x^2 + 1)(x^2 – 1)
(y-3)(y+3)(y^2+9) – (y^2 +2 )(y^2 – 2)
Rút gọn biểu thức:
(x-2)^2 + x(x^2+x+1)-x(x-2)(x+2)
(2x +3)^2+(2x-3)^2 -2(2x+3)(2x-3)
x(x+4)(x-4) -(x^2 + 1)(x^2 – 1)
(y-3)(y+3)(y^2+9) – (y^2 +2 )(y^2 – 2)
`(x-2)^2 +x(+x^2 +x+1)-x(x-2)(x+2)`
`=x^2 -4x+4+x^3 +x^2 +x -x(x^2 -4)`
`=x^2 -4x+4+x^3 +x^2 +x-x^3 +4x`
`=2x^2 +x+4`
`(2x+3)^2 +(2x-3)^2 -2(2x+3)(2x-3)`
`=4x^2 +12x +9 +4x^2 -12x+9 -2(4x^2 -9)`
`=8x^2 +18-8x^2 +18`
`=36`
`x(x+4)(x-4)-(x^2 +1)(x^2 -1)`
`=x(x^2 -16)-(x^4 -1)`
`=x^3 -16x -x^4 +1`
`=-x^4 +x^3 -16x+1`
`(y-3)(y+3)(y^2 +9)-(y^2 +2)(y^2 -2)`
`=(y^2 -9)(y^2 +9)-(y^4 -4)`
`=y^4 -81 -y^4 +4`
`=-77`
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