2002的正约数有______个.
∵2002=2×7×11×13,
∴根据约数个数定理可得:
2002的正约数有(1+1)(1+1)(1+1)(1+1)=16.
故答案为:16.
Read and choose.(选择词语填空。注意英语句子的格式。)
what which when who why
1. — do you do at 8:00 in the morning every day?
— I do exercises.
2. — does your's brother like winter?
— Because he likes skating best.
3. — is playing football on the playground now?
— John with his friends .
4. — season do you like best?
— It's fall.
5. — is your father's birthday?
— It's in March.
关于x的一元二次方程(a-1)x2+x+a2-1=0有一个根是0,则a=()。