5×5×5-7×5×3脱式计算5×5×5-7×5×3=5*(25-21)=5*4=20
5×5×5-7×5×3脱式计算=5x(5x5-7x3) 乘法分配律=5x(25-21)=5x4=20
5×5×5-7×5×3=5×(5×5-7×3)=5×(25-21)=5×4=20
5×5×5-7×5×3=125-105=20
5×(25-21)=5×4=20