原式=3.14x4x4x3x1/3-3.14x3x3x4x1/3=3.14x4x4x(3x1/3)-3.14x3x4x(3x1/3)=3.14x4x4x1-3.14x3x4x1=3.14x16-3.14x12=3.14x4=12.56供参考。
