Xét xem tổng (hiệu) sau là số nguyên tố hay hợp số? Vì sao?
a) 3. 4. 5 + 6. 7 b) 7. 9. 11. 13 – 2. 3. 4. 7
c) 3. 5. 7 + 11. 13. 17 d) 16 354 + 67 541
e) 1. 3. 5. 7. … . 13 + 20 f) 147. 247. 347 – 13
h) 1. 3. 5. 7. … . 13 + 20
\(\frac{3-\frac{3}{20}+\frac{3}{13}-\frac{7}{2013}}{7-\frac{7}{20}+\frac{7}{13}-\frac{7}{2013}}\)=?
Thực hiên phép tíh : (tíh nhah nếu đc)
20/7 x 13/8 + 71/8 x 20/8 - 13/8 x 20/7
Tính:
A=\(\frac{3-\frac{3}{20}+\frac{3}{13}-\frac{3}{2013}}{7-\frac{7}{20}+\frac{7}{13}-\frac{7}{2013}}\)
1) 15 - 98 + 91 - 75 + 98 - 91 - 13
2) 5 - ( 4 - 7 + 12 ) + ( 4 - 7 + 12 ) - 10
3) 20 - ( 25 - 98 + 12 ) + ( 25 - 98 - 72 )
4) - ( 17 - 4 + 13 + | -17 | + 13 )
5) | -16 | - ( 5 - 8 + 7) - ( - 5 ) - 8
6) -20 + ( 3 - 16 + 7 ) - ( 3 - 16 + 7 )
7) 32 - ( 5 - 8 + 32 ) + ( 5 - 8 + 6 )
8) -20 - ( 25 - 11 + 8 ) + ( 25 - 8 + 20 )
\(\frac{\text{7- 7/20 + 7/13 - 7/2019}}{\text{ 11- 11/20 +11/13 - 11/2019}}\)
ai nhanh tick
tính C=4-1/5+4/13-4/2013 trên 7-7/20+7/13-7/2013
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
Tính:
\(\frac{3-\frac{3}{20}+\frac{3}{13}-\frac{3}{2018}}{7-\frac{7}{20}+\frac{7}{13}-\frac{7}{2018}}\)
GIÚP MÌNH VỚI!!!!!!!!!!MÌNH CẦN GẤP LẮM!!!!!!!!!!!!!!!!!!!!!
Tìm x,y € Z* sao cho 1/ x + y/2 = 5/8
Tính
C= 3-3/20 + 3/13 - 3/ 2013
7- 7/20 + 7/ 13- 7/ 2013