初一数学化简求值题,m和n后面的2是平方8mn－〔4m2n-(6mn2+mn)〕-29mn2

^2意思是 平方
8mn－〔4m^2n-(6mn^2+mn)〕-29mn^2
首先 先画括号里的
〔4m^2n-(6mn^2+mn)〕
=4m^2n-6mn^2-mn
然后
8mn－〔4m2n-(6mn2+mn)〕-29mn2
=8mn+4m^2n+6mn^2+mn-29mn^2
=9mn-23mn^2+4m^2n
提出 mn
最后
=mn(9-23n +4m)

=8mn-(4m²n-6mn²-mn)-29mn²
=8mn-4m²n+6mn²+mn-29mn²
=9mn-4m²n-23mn²
或者你可以把mn提出去...

8mn－[4m²n－（6mn²＋mn）]－29mn²
＝8mn－[4m²n－6mn²－mn]－29mn²
＝8mn－4m²n＋6mn²＋mn－29mn²
＝9mn－4m²n－23mn²

-4m2n-23mn2+9mn