神马品牌网高中数学最好的辅导书:这个~~~~~~计算
来源：百度文库 编辑：神马品牌网 时间：2024/04/29 01:07:17
1。(2a-3b+1)²
2。[a-(1/6)b][2a+(1/3)b][3a²+(1/12)b²]
3。[1-(1/2²)][1-(1/3²)][1-(1/4²)]...[1-(1/9²)][1-(1/10²)]
2。[a-(1/6)b][2a+(1/3)b][3a²+(1/12)b²]
3。[1-(1/2²)][1-(1/3²)][1-(1/4²)]...[1-(1/9²)][1-(1/10²)]
1]直接用公式
=4a^2+9b^2+1+4a-6b-12ab
2]
=6[a-(1/6)b][a+(1/6)b][a^2+(1/36)b^2]
=6[a^2-(1/36)b^2][a^2+(1/36)b^2]
=6[a^4-(1/1296)b^4]
=6a^4-(1/216)b^4
3]
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)……(1-1/9)(1+1/9)(1-1/10)(1+1/10)
=(1/2)(3/2)(2/3)(4/3)(3/4)(5/4)……(8/9)(10/9)(9/10)(11/10)
=(1/2)(11/10)
=11/20
1、4a平方+9b平方-12ab+4a-6b+1
2、5a平方+(1/36)b平方
3、11/20