数学题求解······ 好了,加分······· 每一步写清楚

问题描述:

数学题求解······ 好了,加分······· 每一步写清楚
(1) (a+b-3)(a-b+3)
(2) (m²+n-7)(m²-n-7)
(3) (a²+b)(a²-b)
(4) (-4m²+5)(4m²+5)
(5) (x²-y²)(x²+y²)
(6) (9a²+7b²)(7b²-9a²)
````````分`````````````割````````````````线```````````````
(7)(2m+3)(2m-3)
(8) x(x+1)+(2-x)(2+x)
(9) (3x-y)(3x+y)+y(x+y)
(10) (a+ 1\2 b)(a - 1\2 b) -(3a-2b)(3a+2b)

1.a²-(b-3)²=a²-b²+6b-92.(m²-7)²-n²3.(a²)²-b²4.25-(4m²)²5.(x²)²-(y²)²6.(7b²)²-(9a²)²7.4m²-98.x&...过程详细一点,,,详细的话,给你加分全部都是直接应用平方差公式的:(a+b)(a-b)=a^2-b^2 像第一题有点变化,(a+b-3)(a-b+3)看成[a+(b-3)]*[a-(b-3)],代入公式就得到了a²-(b-3)² 剩下的就只是化简了,还有不清楚的吗每一步都详细写,我给你加分,15分再加10分,只要过程详细,贴了个图片,看得见么??