Question

38×29×38=？（递等式，用简便方法计算）

必须简便！！！！！！很急的！！！！！！！

Answer 1

38x29x38=30x38x38-38x38
38x38=40x38-2x38
40x38=40x40-2x40
综上，38x29x38=30x40x40-2x40-2x38-40x40-2x40-2x38

或者
38x29x38=38x38x29=（30x30+2x30x8+8x8）x（30-1）

Answer 2

那就应该是
38×30×38-38×1×38.
=1,444×30-1,444
=43,320-1444
=41,876

Answer 3

38×29×38
=(40-2)*(40-2)*29
=(1600-160+4)*(30-1)
=1444*30-1444
=43320-1444
=41876

Answer 4

38×29×38
=(40-2)*(40-2)*29
=(1600-160+4)*(30-1)
=1444*30-1444
=43320-1444
=41876