算数题2道1.(2a+3b-c)*(2a-3b+c) 2.(2m-3n)平方*(2m+3n)平方
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|:Wvm`KifQ 算数题2道1.(2a+3b-c)*(2a-3b+c) 2.(2m-3n)平方*(2m+3n)平方 算数题2道1.(2a+3b-c)*(2a-3b+c) 2.(2m-3n)平方*(2m+3n)平方 这两道就是平方差的运算 第二题还要幂函数 1.原式=[2a+(3b-c)][2a-(3b-c)]=4a^2-(3b-c)^2=4a^2-9b^2+6bc-c^2 .(2a+3b-c)*(2a-3b+c)
算数题2道
1.(2a+3b-c)*(2a-3b+c) 2.(2m-3n)平方*(2m+3n)平方
(2a+3b-c)*(2a-3b+c)
=[2a+(3b-c)][2a-(3b-c)]
=4a^2-(3b-c)^2
=4a^2-(9b^2+c^2-6bc)
=4a^2-9b^2-c^2+6bc
(2m-3n)平方*(2m+3n)平方
=[(2m-3n)(2m+3n)]^2
=(4m^2-9n^2)^2
=16m^4+81n^4-72m^2*n^2
注意:^表示次方.
1.(2a+3b-c)*(2a-(3b-c))
=(2a)^2-(3b-c)^2
=4a^2-9b^2-c^2+6bc
2.(2m-3n)^2*(2m+3n)^2
=[(2m-3n)(2m+3n)]^2
=(4m^2-9n^2)^2
=16m^4+81n^4-72m^2n^2 我没抄。。想不到一样
2.原式=[(2m-3n)(2m+3n)]^2=(4m^2-9n^2)^2=16m^4-72m^2*n^2+81n^4
=[2a+(3b-c)]*[2a-(3b-c)]
=4a²-(3b-c)²
.(2m-3n)平方*(2m+3n)平方
=【(2m-3n)(2m+3n)】²
=(4m²-9n²)²