求解题:多项式相乘请大家帮个忙,帮我算一下,下列多项式相乘,要有算法,算出两三题也可以:(“·”为乘号,1/2即为二分之一)(1) (2x+3)·(3x+2)·(x-2)(2) (1/2xy + 4/3x的平方)·(-2/3y·x的平方 - 3/4x·
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![求解题:多项式相乘请大家帮个忙,帮我算一下,下列多项式相乘,要有算法,算出两三题也可以:(“·”为乘号,1/2即为二分之一)(1) (2x+3)·(3x+2)·(x-2)(2) (1/2xy + 4/3x的平方)·(-2/3y·x的平方 - 3/4x·](/uploads/image/z/2544522-42-2.jpg?t=%E6%B1%82%E8%A7%A3%E9%A2%98%EF%BC%9A%E5%A4%9A%E9%A1%B9%E5%BC%8F%E7%9B%B8%E4%B9%98%E8%AF%B7%E5%A4%A7%E5%AE%B6%E5%B8%AE%E4%B8%AA%E5%BF%99%2C%E5%B8%AE%E6%88%91%E7%AE%97%E4%B8%80%E4%B8%8B%2C%E4%B8%8B%E5%88%97%E5%A4%9A%E9%A1%B9%E5%BC%8F%E7%9B%B8%E4%B9%98%2C%E8%A6%81%E6%9C%89%E7%AE%97%E6%B3%95%2C%E7%AE%97%E5%87%BA%E4%B8%A4%E4%B8%89%E9%A2%98%E4%B9%9F%E5%8F%AF%E4%BB%A5%EF%BC%9A%EF%BC%88%E2%80%9C%C2%B7%E2%80%9D%E4%B8%BA%E4%B9%98%E5%8F%B7%2C1%2F2%E5%8D%B3%E4%B8%BA%E4%BA%8C%E5%88%86%E4%B9%8B%E4%B8%80%EF%BC%89%281%29+%282x%2B3%29%C2%B7%283x%2B2%29%C2%B7%28x-2%29%282%29+%281%2F2xy+%2B+4%2F3x%E7%9A%84%E5%B9%B3%E6%96%B9%29%C2%B7%28-2%2F3y%C2%B7x%E7%9A%84%E5%B9%B3%E6%96%B9+-+3%2F4x%C2%B7)
求解题:多项式相乘请大家帮个忙,帮我算一下,下列多项式相乘,要有算法,算出两三题也可以:(“·”为乘号,1/2即为二分之一)(1) (2x+3)·(3x+2)·(x-2)(2) (1/2xy + 4/3x的平方)·(-2/3y·x的平方 - 3/4x·
求解题:多项式相乘
请大家帮个忙,帮我算一下,下列多项式相乘,要有算法,算出两三题也可以:(“·”为乘号,1/2即为二分之一)
(1) (2x+3)·(3x+2)·(x-2)
(2) (1/2xy + 4/3x的平方)·(-2/3y·x的平方 - 3/4x·y的平方+ 7/6x的平方)
(3) 解方程:-x·(x+6)=3x-(x-3)·(x+4)
(4)已知:f(y)=1/2·a的四次方·y的二次方 - 1/3a的三次方·y的三次方-1/4a的平方·y的四次方,求:f(y)·(-2/3a的平方·y的平方)
(5)化简:3x的平方·y - [xy·(3x+2y) - 2y·(xy-y)],并求当 x=5 , y=-2时的值
求解题:多项式相乘请大家帮个忙,帮我算一下,下列多项式相乘,要有算法,算出两三题也可以:(“·”为乘号,1/2即为二分之一)(1) (2x+3)·(3x+2)·(x-2)(2) (1/2xy + 4/3x的平方)·(-2/3y·x的平方 - 3/4x·
(1) (2x+3)(3x+2)(x-2)
=(6x^2+13x+6)(x-2)
=6x^3+x^2-20x-12
(2) (1/2xy + 4/3x^2)(-2/3yx^2 - 3/4xy^2+ 7/6x^2)
=14/9x^4+7/12x^3y-8/9x^4y-4/3x^3y^2-3/8x^2y^3
(3) 解方程:-x(x+6)=3x-(x-3)(x+4)
解: -x^2-6x=3x-x^2-x+12
-8x=12
x=-3/2
(4)已知:f(y)=1/2·a^4·y^2 - 1/3a^3·y^3-1/4a^2·y^4,
求:f(y)·(-2/3a的平方·y的平方)
f(y)(-2/3a^2y^2)=(1/2·a^4·y^2 - 1/3a^3·y^3-1/4a^2·y^4)(-2/3a^2y^2)
=-1/3a^6y^4+2/9a^5y^5+1/6a^4y^6
(5)化简:3x的平方·y - [xy·(3x+2y) - 2y·(xy-y)],并求当 x=5 , y=-2时的值
3x^2y - [xy(3x+2y)-2y(xy-y)]
=3x^2y-3x^2y-2xy^2+2xy^2-2y^2
=-2y^2
当 y=-2时
-2y^2=-2(-2)^2
=-8