计算题(1)(2x-3y)^2(2x+3y)^2简便计算(2)999^2-1002*998因式分解(3)-20x^3+60x^2y-45xy^2(4)(x^2+2x)(x^2+2x-11)+24先化简再求值:(5x-3)(5x+3)+(3x-2)(4-6x)-(3x-1)(3x+2),其中x=-2
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/26 02:45:09
![计算题(1)(2x-3y)^2(2x+3y)^2简便计算(2)999^2-1002*998因式分解(3)-20x^3+60x^2y-45xy^2(4)(x^2+2x)(x^2+2x-11)+24先化简再求值:(5x-3)(5x+3)+(3x-2)(4-6x)-(3x-1)(3x+2),其中x=-2](/uploads/image/z/764641-1-1.jpg?t=%E8%AE%A1%E7%AE%97%E9%A2%98%EF%BC%881%EF%BC%89%EF%BC%882x-3y%29%5E2%282x%2B3y%29%5E2%E7%AE%80%E4%BE%BF%E8%AE%A1%E7%AE%97%282%29999%5E2-1002%2A998%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%283%29-20x%5E3%2B60x%5E2y-45xy%5E2%284%29%28x%5E2%2B2x%29%28x%5E2%2B2x-11%29%2B24%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BC%3A%EF%BC%885x-3%29%285x%2B3%29%2B%283x-2%29%284-6x%29-%283x-1%29%283x%2B2%29%2C%E5%85%B6%E4%B8%ADx%3D-2)
计算题(1)(2x-3y)^2(2x+3y)^2简便计算(2)999^2-1002*998因式分解(3)-20x^3+60x^2y-45xy^2(4)(x^2+2x)(x^2+2x-11)+24先化简再求值:(5x-3)(5x+3)+(3x-2)(4-6x)-(3x-1)(3x+2),其中x=-2
计算题(1)(2x-3y)^2(2x+3y)^2
简便计算
(2)999^2-1002*998
因式分解
(3)-20x^3+60x^2y-45xy^2
(4)(x^2+2x)(x^2+2x-11)+24
先化简再求值:(5x-3)(5x+3)+(3x-2)(4-6x)-(3x-1)(3x+2),其中x=-2
计算题(1)(2x-3y)^2(2x+3y)^2简便计算(2)999^2-1002*998因式分解(3)-20x^3+60x^2y-45xy^2(4)(x^2+2x)(x^2+2x-11)+24先化简再求值:(5x-3)(5x+3)+(3x-2)(4-6x)-(3x-1)(3x+2),其中x=-2
999^2-1002*998
=(1000-1)^2-(1000+2)(1000-2)
=1000^2-2000+1^2-(1000^2-2^2)
=1000000-2000+1-1000000+4
=5-2000
=-1995
(3)-20x^3+60x^2y-45xy^2
=-5x(4x^2-12xy+9y^2)
=-5X(2X-3Y)^2
(4)(x^2+2x)(x^2+2x-11)+24
=(x^2+2x)^2-11(x^2+2x)-24
=(x^2+2x-3)(x^2+2x-8)
先化简再求值:(5x-3)(5x+3)+(3x-2)(4-6x)-(3x-1)(3x+2),其中x=-2
25X^2-9-2(2-3X)(2-3X)-(3X-1)(3X-2)
=25X^2-9-2(4-6X+9X^2)-(9X^2-3X+2)
=25X^2-9-8+12X-18X^2-9X^+3X-2
=-2X^2+15X-19
=-2*4-15*2-19
=-57