先分解因式,再求值(在线等,1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/82)(a²)²-4a³b+4a²b²,其中a=8,b=-2
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![先分解因式,再求值(在线等,1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/82)(a²)²-4a³b+4a²b²,其中a=8,b=-2](/uploads/image/z/10386536-32-6.jpg?t=%E5%85%88%E5%88%86%E8%A7%A3%E5%9B%A0%E5%BC%8F%2C%E5%86%8D%E6%B1%82%E5%80%BC%EF%BC%88%E5%9C%A8%E7%BA%BF%E7%AD%89%2C1%EF%BC%89%EF%BC%882x%2B3y%EF%BC%89%26sup2%3B-%EF%BC%882x-3y%EF%BC%89%26sup2%3B%2C%E5%85%B6%E4%B8%ADx%3D1%2F6%2Cy%3D1%2F82%EF%BC%89%EF%BC%88a%26sup2%3B%29%26sup2%3B-4a%26sup3%3Bb%2B4a%26sup2%3Bb%26sup2%3B%2C%E5%85%B6%E4%B8%ADa%3D8%2Cb%3D-2)
先分解因式,再求值(在线等,1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/82)(a²)²-4a³b+4a²b²,其中a=8,b=-2
先分解因式,再求值(在线等,
1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/8
2)(a²)²-4a³b+4a²b²,其中a=8,b=-2
先分解因式,再求值(在线等,1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/82)(a²)²-4a³b+4a²b²,其中a=8,b=-2
(2x+3y)²-(2x-3y)²
=[(2x+3y)+(2x-3y)][(2x+3y)-(2x-3y)]
=(2x+3y+2x-3y)(2x+3y-2x+3y)
=4x×6y
=24xy
当x=1/6,y=1/8时
24xy
=24×1/48
=1/2
(a²)²-4a³b+4a²b²
=a²(a²-4ab+4b²)
=a²(a-2b)²
当a=8,b=-2时
=64×12²
=64×144
=9216
1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/8
(2x+3y)²-(2x-3y)²
=[(2x+3y)-(2x-3y)][(2x+3y)+(2x-3y)]
=6y*4x
=24xy
=24*1/6*1/8
=24/48
=1/2
2)(a²)²-4a&su...
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1)(2x+3y)²-(2x-3y)²,其中x=1/6,y=1/8
(2x+3y)²-(2x-3y)²
=[(2x+3y)-(2x-3y)][(2x+3y)+(2x-3y)]
=6y*4x
=24xy
=24*1/6*1/8
=24/48
=1/2
2)(a²)²-4a³b+4a²b²,其中a=8,b=-2
(a²)²-4a³b+4a²b²
=a^4--4a^3b+4a^2b^2
=a^2(a^2-4ab+4b^2)
=a^2(a-2b)^4
=8^2*(8+2*2)^2
=8^2*12^2
=64*144
=9216
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