代数式化简、求值一.化简x²y-3xy²+2yx²+y²x5(a²b-
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代数式化简、求值
一.化简
x²y-3xy²+2yx²+y²x
5(a²b-3ab²)-2(a²b-7ab²)
二.化简、求值
(1)(4a+3a²-3+3a³)-(-a+4a³),a=-2
(2)(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y²-3xy²)]
谢谢
一.化简
x²y-3xy²+2yx²+y²x
5(a²b-3ab²)-2(a²b-7ab²)
二.化简、求值
(1)(4a+3a²-3+3a³)-(-a+4a³),a=-2
(2)(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y²-3xy²)]
谢谢
1.x²y-3xy²+2yx²+y²x
=(x²y+2yx²)-(3xy²-y²x)
=3yx²-2xy²
=(3yx+2xy)(3yx-2xy)
=5xy²
5(a²b-3ab²)-2(a²b-7ab²)
=5a²b-15ab²-2a²b+14ab²
=3a²b-ab²
2.(1)(4a+3a²-3+3a³)-(-a+4a³)=(-8+12-3-24)-(2-32)
=7
(2)(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y²-3xy²)]=
=(x²y+2yx²)-(3xy²-y²x)
=3yx²-2xy²
=(3yx+2xy)(3yx-2xy)
=5xy²
5(a²b-3ab²)-2(a²b-7ab²)
=5a²b-15ab²-2a²b+14ab²
=3a²b-ab²
2.(1)(4a+3a²-3+3a³)-(-a+4a³)=(-8+12-3-24)-(2-32)
=7
(2)(2x²y-2xy²)-[(-3x²y²+3x²y)+(3x²y²-3xy²)]=
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