Tính nhanh
10+2+4+6+8+20
1/3 + 1/6 + 4/3 + 2/6 + 2/3 + 5/6
Tính nhanh :
1/2 + 2/4 + 3/6 + 4/8 + 5/10 + 6/12 =
1/3 + 1/4 + 1/5 + 8/10 + 20/15 + 20/30 =
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
4 5. 4. 6.
--- + --- --- + ---
15 6. 5. 7
3. 4. 2. 5
--- + --- --- + ---
5. 20. 5. 12
3/4 x ( 5/6 + 7/8)
B)1/11 : (6/7 - 5/6) - 20/11
D) (4 - 2/7 x3) : 1/3
1/2+2/4+3/6+4/8+5/10+6/12+7/14+8/16+9/18+ 10/20
6/16:3/6 < x < 20/21 : 4/21
8/21 x 7 /2 < x < 11/8 x 4
6/16:3/6 < x < 20/21 : 4/21
8/21 x 7 /2 < x < 11/8 x 4
a) Tính bằng hai cách:
(15 +35) : 5;
(80 +4) : 4
b) Tính bằng hai cách (theo mẫu)
Mẫu: 12 : 4 + 20 : 4 = ?
Cách 1:
12 : 4 + 20 : 4
= 3 + 5 = 8
Cách 2:
12 : 4 + 20 : 4
= (12+20) : 4
= 32 :4 = 8
18 : 6 + 24 : 6;
60 : 3 + 9 : 3.
bài 6:rút gọn rồi tính
a.5/6 - 2/14
b. 5/20 - 1/6
c. 5/9 - 3/12
d. 8 - 4/6
help me : (