因式分解(1) -2x+12x平方-18x三次 (2)(x+2)(-x+2)-(x+1)(x-3)(3)[(x-3y)²-(x+3y)²]÷(-2xy)
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因式分解(1) -2x+12x平方-18x三次 (2)(x+2)(-x+2)-(x+1)(x-3)(3)[(x-3y)²-(x+3y)²]÷(-2xy)
因式分解
(1) -2x+12x平方-18x三次 (2)(x+2)(-x+2)-(x+1)(x-3)
(3)[(x-3y)²-(x+3y)²]÷(-2xy)
因式分解(1) -2x+12x平方-18x三次 (2)(x+2)(-x+2)-(x+1)(x-3)(3)[(x-3y)²-(x+3y)²]÷(-2xy)
-2x+12x平方-18x三次
=-2x+12x²-18x³
=-2x(9x²-6x+1)
=-2x(3x-1)²
(x+2)(-x+2)-(x+1)(x-3)
=(x+2)(2-x)-(x²-2x-3)
=4-x²-x²+2x+3
=-2x²+2x+7
[(x-3y)²-(x+3y)²]÷(-2xy)
=(x-3y+x+3y)(x-3y-x-3y)÷(-2xy)
=2x(-6y)÷(-2xy)
=-12xy÷(-2xy)
=6
(1)-2X+12X²-18X³
=-2X(1-6X+9X²)
=-2X(1-3X)²或=2X(3X-1)²
(2)(X+2)(-X+2)-(X+1)(X-3)
=(-X²+4)-(X²-2X-3)
=-X²+4-X²+2X+3
=-2X²+2X+7<...
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(1)-2X+12X²-18X³
=-2X(1-6X+9X²)
=-2X(1-3X)²或=2X(3X-1)²
(2)(X+2)(-X+2)-(X+1)(X-3)
=(-X²+4)-(X²-2X-3)
=-X²+4-X²+2X+3
=-2X²+2X+7
(这题不是因式分解吧!要不就抄错了)
(3)〔(X-3Y)²-(X+3Y)²〕÷(-2XY)
=〔(X-3Y)+(X+3Y)〕〔(X-3Y)-(X+3Y)〕÷(-2XY)
=(X-3Y+X+3Y)(X-3Y-X-3Y)÷(-2XY)
=2X·(-6Y)÷(-2XY)
=-12XY÷(-2XY)
=6 (这是道计算题吧!)
收起
没悬赏,那么多要求!
(1)
原式=-2x(9x²-6x+1)
=-2x(3x-1)²
(2)
原式=7-2x²+2x
=
(3)
原式={[(x-3y)-(x+3y)][(x-3y)+(x+3y)]}/(-2xy)
=-12xy/(-2xy)
=6
就这样吧!!
(1)原式=2x(-1+6x-9x^2)=2x(-3x+1)(3x-1)
(3)原式=【(x-3y+x-3y)(x-3y-x-3y)】÷(-2xy)=6
望采纳,谢谢