(5a²-3b²)-3(a²-b²)-(-b²),其中a=5,b=-35x²-(3y²+5x²)+(4y²+3xy),其中x=-1,y=1/3计算:2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy²}
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![(5a²-3b²)-3(a²-b²)-(-b²),其中a=5,b=-35x²-(3y²+5x²)+(4y²+3xy),其中x=-1,y=1/3计算:2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy²}](/uploads/image/z/4322119-31-9.jpg?t=%EF%BC%885a%26%23178%3B-3b%26%23178%3B%EF%BC%89-3%EF%BC%88a%26%23178%3B-b%26%23178%3B%EF%BC%89-%EF%BC%88-b%26%23178%3B%EF%BC%89%2C%E5%85%B6%E4%B8%ADa%3D5%2Cb%3D-35x%26%23178%3B-%EF%BC%883y%26%23178%3B%2B5x%26%23178%3B%EF%BC%89%2B%EF%BC%884y%26%23178%3B%2B3xy%EF%BC%89%2C%E5%85%B6%E4%B8%ADx%3D-1%2Cy%3D1%2F3%E8%AE%A1%E7%AE%97%EF%BC%9A2x%26%23178%3By%2B%EF%BD%9B2xy-%5B3x%26%23178%3By-2%EF%BC%88-3x%26%23178%3By%2B2xy%EF%BC%89%5D-4xy%26%23178%3B%EF%BD%9D)
(5a²-3b²)-3(a²-b²)-(-b²),其中a=5,b=-35x²-(3y²+5x²)+(4y²+3xy),其中x=-1,y=1/3计算:2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy²}
(5a²-3b²)-3(a²-b²)-(-b²),其中a=5,b=-3
5x²-(3y²+5x²)+(4y²+3xy),其中x=-1,y=1/3
计算:2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy²}
(5a²-3b²)-3(a²-b²)-(-b²),其中a=5,b=-35x²-(3y²+5x²)+(4y²+3xy),其中x=-1,y=1/3计算:2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy²}
1、(5a²-3b²)-3(a²-b²)-(-b²)
=5a²-3b²-3a²+3b²+b²
=2a²+b²
当a=5,b=-3时
原式=50+9=59
2、5x²-(3y²+5x²)+(4y²+3xy),
=5x²-3y²-5x²+4y²+3xy
=y²+3xy
当x=-1,y=1/3时
原式=1/9-1=-8/9
计算:2x²y+{2xy-[3x²y-2(-3x²y+2xy)]-4xy²}
=2x²y+2xy-3x²y-6x²y+4xy-4xy²
=-7x²y+6xy-4xy²