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初一4道计算题(1).(-1/2x+2y)^2(2).4(-3/2x-3y)(3/2x-3y)(3).x^2-(x+2)

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初一4道计算题
(1).(-1/2x+2y)^2
(2).4(-3/2x-3y)(3/2x-3y)
(3).x^2-(x+2)(x-2)
(4).(x/2+5)^2-(x/2-5)^2
初一4道计算题(1).(-1/2x+2y)^2(2).4(-3/2x-3y)(3/2x-3y)(3).x^2-(x+2)
(1).(-1/2x+2y)^2
=1/4x^2-xy+4y^2
(2).4(-3/2x-3y)(3/2x-3y)
=-9x^2+36xy+36Y^2
(3).x^2-(x+2)(x-2)
=x^2-x^2+4
=4
(4).(x/2+5)^2-(x/2-5)^2
=(x/2+5+x/2-5)(x/2+5-x/2+5)
=10x