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整式的乘法!(3m+2n-1)(3m-2n+1)(5x-7)(7x-5)(x-1)(x-2)-(x-3)(x+4)

题目详情
整式的乘法!
(3m+2n-1)(3m-2n+1)
(5x-7)(7x-5)
(x-1)(x-2)-(x-3)(x+4)
▼优质解答
答案和解析
3m+2n-1)(3m-2n+1) =[3m+(2n-1)][3m-(2n-1)] =(3m)^2-(2n-1)^2 =9m^2-4n^2+4n-1 (5x-7)(7x-5) =5x*7x-5x*5-7*7x+(-7)*(-5) =35x^2-74x+35 (x-1)(x-2)-(x-3)(x+4) =(x^2-3x+2)-(x^2+x-12) =x^2-3x+2-x^2-x+12 =-4x+14...