质因子

lingdang1988

这是一月份的JJ,

5. 5^40 + 5^37 有几个质因子？　the answer is 4.

答案是怎么就出来的？　谁能告诉我质因子是什么意思吗？我一遇到因子或质因子的题就头晕．　Can anyone help me to solve
this kind of problem? Is there any easy way for me to solve, and I
won't be afraid of this type of questions in the future?

applebees

ding !!!!!!!!

himba

5^37(5^3+1)=5^37*126=5^37*2*7*9

so,质因子有2,5,7,9

思路也就是化成质数乘积