Question

Question 2:
The number of factors of 120 is

Question 5:
Find four integer numbers a,b,c,d such that
a + b + c + d = 1
a + c + d = 2
a + b + d = 3
a + b + c = 4
Answer: (a;b;c;d)=() 

Question 6:
The 215^th  term of the expression A=1-7+13-19+25-31+⋯ is

Question 7:
A natural number will be increased by 9 times ifthe digit 0 is written between tens digit and units digit.The number is

Question 8:
Calculate: 1×2+2×3+⋯+100×101=

Question 9:
The root of the equation (x+1)+(x+2)+(x+3)+⋯+(x+100)=5750 is x=

Question 10:
The sum of digits of 3¹⁰⁰⁰ is A,the sum of digits of A is B,and the sum of digits of B is C.The value of C is

Answer 1

2: Ước của 120 là:

{1;2;3;4;5;6;8;10;12;15;20;24;30;40;60;120}

9: x+ (1+2+3+4+...+100) = 5750

    x + 5050= 5750

     x = 5750 - 5050 = 700

6. Chữ số thứ 215 là 1285

Answer 2

cau 2 la co 16 uoc

cau 5 a=7 b=-1 c=-2 d=-3