數學題不懂做,教下我plz

Q1.3x3x7x7,2x3x3x5x7

3,7 are common factors
2,3,5,7 are common factors
common factors of both numbers are 3 and 7
Highest common factor is 7

2011-09-27 22:14:22 補充：
3,7 are factors
2,3,5,7 are factors
common factors of both numbers are 3 and 7
Highest common factor is 7

3x3x7x7=441 2x3x3x5x7=630

441 ,630最大公因數=9