初中 因式分解!①(x^2-5)^2-16x^2②4yx^3+4(xy)^2+xy^3③x^2-10x+24先化简再求值:[(x+2y)(x-2y)-(x+4y)^2]÷4y,其中x=5,y=2
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![初中 因式分解!①(x^2-5)^2-16x^2②4yx^3+4(xy)^2+xy^3③x^2-10x+24先化简再求值:[(x+2y)(x-2y)-(x+4y)^2]÷4y,其中x=5,y=2](/uploads/image/z/1851326-62-6.jpg?t=%E5%88%9D%E4%B8%AD+%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%21%E2%91%A0%28x%5E2-5%29%5E2%EF%BC%8D16x%5E2%E2%91%A14yx%5E3%2B4%28xy%29%5E2%2Bxy%5E3%E2%91%A2x%5E2-10x%2B24%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BC%3A%5B%28x%2B2y%29%28x-2y%29%EF%BC%8D%28x%2B4y%29%5E2%5D%C3%B74y%2C%E5%85%B6%E4%B8%ADx%3D5%2Cy%3D2)
初中 因式分解!①(x^2-5)^2-16x^2②4yx^3+4(xy)^2+xy^3③x^2-10x+24先化简再求值:[(x+2y)(x-2y)-(x+4y)^2]÷4y,其中x=5,y=2
初中 因式分解!
①(x^2-5)^2-16x^2
②4yx^3+4(xy)^2+xy^3
③x^2-10x+24
先化简再求值:[(x+2y)(x-2y)-(x+4y)^2]÷4y,其中x=5,y=2
初中 因式分解!①(x^2-5)^2-16x^2②4yx^3+4(xy)^2+xy^3③x^2-10x+24先化简再求值:[(x+2y)(x-2y)-(x+4y)^2]÷4y,其中x=5,y=2
①(x^2-5)^2-16x^2
=(x^2-5-4x)(x^2-5+4x)
=(x-5)(x+1)(x-1)(x+5)
②4yx^3+4(xy)^2+xy^3
=xy(4x^2+4xy+y^2)
=xy(2x+y)^2
③x^2-10x+24
=(x-4)(x-6)
先化简再求值:[(x+2y)(x-2y)-(x+4y)^2]÷4y,其中x=5,y=2
[(x+2y)(x-2y)-(x+4y)^2]÷4y
=[x^2-4y^2-x^2-16y^2-8xy]÷4y
=(-12y^2-8xy)/(4y)
=-3y-2x
=-3*2-2*5
=-16
①原式=(x^2-5-4X)(x^2-5+4X)
=(x-5)(x+1)(x+5)(x-1)
②原式=xy[4x^2+4(xy)^2+y^2]
=xy(2x+y)^2
③原式=(x-4)(x-6)
原式等于(x^2-4y^2-x^2-8xy+16y^2)÷4y
=(12y^2-8xy)÷4y
=3y-2x
代入得-4
1.(X+1)*(X-1)*(X+5)*(X-5)