x-1 mũ 3=27

X-1 mũ 3= 3 mũ 3

=> x-1=3

X= 3+1=4

Vậy x=4.

1+2-2-2+4+5+6-7-8+9+...+994-995-996+997+998

=1+(2-3-4+5)+(6-7-8+9)+...+(994-995-996+997)+998

=1+0+0+0+...+0+998

=1+998

=999

1. He will get a cup of coffee next morning

2. The teacher won't punish that student

3. If he doesn't eat breakfast, he will be hungry

4. We can reuse bottles and cans

5. We shouldn't throw rubbish on the street

Vì 24;38 chia cho a dư 3

=> 21;35 chia hết cho a

=> a \in∈ ƯC(21;35) = {1;7}

Vậy số cần tìm là 7

D nhé 

D, hình thoi