好几题:(1):X平方(2x)立方-x(3x +8四次方),其中x=-2 PS:(2):(2x-3)(-2x-3)(3):2003X1997(4):(2X+1)(X-1+X(根号2+1-x),其中x=-根号2(5):(x-1)平方+(x+3)(x-3)+(X-3(x-1)其中x平方-2x=2(6):(6a平方-7a平方+36a立方)÷3a平方(7):(-8a四次方b五次方c÷4ab五次方)x(a三次方b平方)(8):-3x立方y·(-2x平方y平方)平方(9):(-5x+3/2)(-5x-1.5)(10):(x+2y-3)(x-2y+3)
好几题:(1):X平方(2x)立方-x(3x +8四次方),其中x=-2 PS:
(2):(2x-3)(-2x-3)
(3):2003X1997
(4):(2X+1)(X-1+X(根号2+1-x),其中x=-根号2
(5):(x-1)平方+(x+3)(x-3)+(X-3(x-1)其中x平方-2x=2
(6):(6a平方-7a平方+36a立方)÷3a平方
(7):(-8a四次方b五次方c÷4ab五次方)x(a三次方b平方)
(8):-3x立方y·(-2x平方y平方)平方
(9):(-5x+3/2)(-5x-1.5)
(10):(x+2y-3)(x-2y+3)
解
(2):(2x-3)(-2x-3)
=-4x^2+6x-6x+9
=-4x^2+9
(3):2003X1997
=[2000+3][2000-3]
=4000000-9
=3999991
(4):(2X+1)(X-1+X(根号2+1-x),其中x=-根号2
=[2x+1][x-1+x√2+1-x]
=[2x+1]xx√2
=2√2x+√2x-√2
x=-√2代入
=-4-2
=-6
(5):(x-1)平方+(x+3)(x-3)+(X-3(x-1)其中x平方-2x=2
=[x-1]^2+[x^2-9]+x-[3x-3]
=x^2-2x+1+x2-9+x-3x+3
=2x^2-4x-5
x^2-2x=2
2[x^2-2x]-5=-1
(6):(6a平方-7a平方+36a立方)÷3a平方
=2-7/3+12a
=12-1/3
(7):(-8a四次方b五次方c÷4ab五次方)x(a三次方b平方)
=-8a^4b^5/4abxa^3b^2
=-2a^3b^4xa^3b^2
=-2a^5b^6
(8):-3x立方y·(-2x平方y平方)平方
=-3x^3y4x^2y^4
=-12x^5y^8
(9):(-5x+3/2)(-5x-1.5)
=[-5x]^2-[1.5]^2
=25x^2-2.25
我晕了,你给我分不
(10):(x+2y-3)(x-2y+3)
=x^2-[2y-3]^2
=x^2-[2y^2-12y+9】
=x^2-2y^2+12y-9
X平方(2x)立方-x(3x +8四次方),其中x=-2
x^2 2x^3 -3x^2-x8^4
=2x^5-3x^2-4096x
x=-2
=-32-12-4096x-2
=-44+8192
=8148