求多项式(1)-3x²+3xy-2/1y²与-2/1x²+4xy-2/3y²的差 下面还有.(2)计算(3x-2y)²(2y-3x)³(2y-3x)4次方 (结果用幂的形式表示)(3)计算:(-x)³(x²) 5次方x-(-x 4次方)²(-
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求多项式(1)-3x²+3xy-2/1y²与-2/1x²+4xy-2/3y²的差 下面还有.(2)计算(3x-2y)²(2y-3x)³(2y-3x)4次方 (结果用幂的形式表示)(3)计算:(-x)³(x²) 5次方x-(-x 4次方)²(-
求多项式(1)-3x²+3xy-2/1y²与-2/1x²+4xy-2/3y²的差 下面还有.
(2)计算(3x-2y)²(2y-3x)³(2y-3x)4次方 (结果用幂的形式表示)
(3)计算:(-x)³(x²) 5次方x-(-x 4次方)²(-x 6次方)
(4)计算:(x-2y)²-(x-2y)(x+2y)
(5)先化解,在求值. (2x-3)(2x+3)-(1-2x)²+(x-1)(x+2),其中x=-2.
大家帮忙做一下,今晚就要,谢谢谢谢!~~~
求多项式(1)-3x²+3xy-2/1y²与-2/1x²+4xy-2/3y²的差 下面还有.(2)计算(3x-2y)²(2y-3x)³(2y-3x)4次方 (结果用幂的形式表示)(3)计算:(-x)³(x²) 5次方x-(-x 4次方)²(-
(1)-3x²+3xy-1/2y²-(-1/2x²+4xy-3/2y²)
=-3x²+3xy-1/2y²+1/2x²-4xy+3/2y²
=x²(-3+1/2)+xy(3-4)+y²(1/2+3/2)
=-5/2x²-xy+2y²
(2)(3x-2y)²(2y-3x)³(2y-3x)4次方
=(2y-3x)(2+3+4)次方
=(2y-3x)9次方
(3)题目表达不清
(4)(x-2y)²-(x-2y)(x+2y)
=(x-2y)(x-2y-x-2y)
=(x-2y)(-4y)
=8y²-4xy
(5)(2x-3)(2x+3)-(1-2x)²+(x-1)(x+2),
=4x²-9-4x²+4x-1+x²+x-2
=x²+5x-12
当x=-2时
x²+5x-12
=(-2)²+5×(-2)-12
=4-10-12
=-18
(1)-3x²+3xy-1/2y²-(-1/2x²+4xy-3/2y²)
=-3x²+3xy-1/2y²+1/2x²-4xy+3/2y²
=x²(-3+1/2)+xy(3-4)+y²(1/2+3/2)
=-5/2x²-xy+2y²
(2)(3x-2...
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(1)-3x²+3xy-1/2y²-(-1/2x²+4xy-3/2y²)
=-3x²+3xy-1/2y²+1/2x²-4xy+3/2y²
=x²(-3+1/2)+xy(3-4)+y²(1/2+3/2)
=-5/2x²-xy+2y²
(2)(3x-2y)²(2y-3x)³(2y-3x)4次方
=(2y-3x)(2+3+4)次方
=(2y-3x)9次方
(3)题目表达不清
(4)(x-2y)²-(x-2y)(x+2y)
=(x-2y)(x-2y-x-2y)
=(x-2y)(-4y)
=8y²-4xy
(5)(2x-3)(2x+3)-(1-2x)²+(x-1)(x+2),
=4x²-9-4x²+4x-1+x²+x-2
=x²+5x-12
当x=-2时
x²+5x-12
=(-2)²+5×(-2)-12
=4-10-12
=-18
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第一题没看懂,你应该加个括号。
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