a) 5/7 + 4/3 + 2/7 + 5/3
b) 17/12 + 29/7 - 8/7 + 7/12
c) 2/5 + 6/9 + 7/4 + 3/5 + 1/3 + 1/4
d) 17/51 + 13/17 + 29/11 + 50/75 + 4/17 + 4/11
10/3...1/3. 10/6...3/8. 17/4...5/6. 1/3...5/9 5/8...7/5 3/4...15/6 10/9...10/11 7/8...7/2 15/9...3/8 15/7...15/8 16/5...16/7 25/11...1
3. Tính rồi rút gọn :
a. 2/5 + 3/4 5/8 + 7/2 4/9 +5/18 5/8 + 9/16
b. 9/5 - 5/9 12/7 -17/2 11/8 - 8/11 17/6 - 6/17
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20=?
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+...100=
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+.....+99999999999956214 (tính tỏng)
1+2-3-4+5+6-7-8+9+10-11-12+13+14-15-16+17+18-19-20...+301+302
Điền dấu : >,<,=
a,5/3 x 7/10 .... 5/7 : 7/10
b, 4/5 x 5/6 ..... 8/9 : 4/3
c, 5/11 x 33/15 ..... 6/17 x 34/25
d, 15/19 x 38/5 ..... 15/16 : 3/8
Mong mn làm giúp ạ
Tính nhanh:
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19