(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)+(1/8-1/9)+(1/9-1/10)
Số ?
2 = 1 + ... 6 = 2 + ... 8 = ...+ 3 10 = 8 + ....
3 = 1 + ... 6 =...+ 3 8 = 4 + .... 10 = ...+ 3
4 = ...+ 1 7 = 1 + ... 9 = ...+ 1 10 = 6 + ...
4 = 2 + ... 7 = ...+ 2 9 = ...+ 3 10 = ...+ 5
5 = ...+ 1 7 = 4 + .... 9 = 7 +.... 10 = 10 + ...
5 = 3 +.... 8 = ...+ 1 9 = 5 + ... 10 = 0 + .....
6 = ...+ 1 8 = 6 + ... 10 = ...+ 1 1 = 1 + ....
2 = 1 + 1 6 = 2 + 4 8 = 5 + 3 10 = 8 + 2
3 = 1 + 2 6 = 3 + 3 8 = 4 + 4 10 = 7 + 3
4 = 3 + 1 7 = 1 + 6 9 = 8 + 1 10 = 6 + 4
4 = 2 + 2 7 = 5 + 2 9 = 6+ 3 10 = 5 + 5
5 = 4 + 1 7 = 4 + 3 9 = 7 + 2 10 = 10 + 0
5 = 3 + 2 8 = 7 + 1 9 = 5 + 4 10 = 0 + 10
6 = 5 + 1 8 = 6 + 2 10 = 9 + 1 1 = 1 + 0
Tiếng việt khó .
1+1+1+1+1+2+3+4+5+6+7+8+9+10 x 1+1+1+1+1+2+3+4+5+6+7+8+9+10 +1+1+1+1+1+2+3+4+5+6+7+8+9+10 - 10 x 9 - 9 + 45 +46 +47 =
1+1+1+1+2+2+2+3+3+3+3+4+4+4+4+5+5+5+5+6+6+6+6+7+7+7+7+8+8+8+8+9+9+9+9+10=
= (1+1+1+1)+(2+2+2)+(3+3+3+3)+(4+4+4+4)+(5+5+5+5)+(6+6+6+6)+(7+7+7+7)+(8+8+8+8)+(9+9+9+9)+10
4 + 6 + 12 + 16 + 20 + 24 + 28 + 32 + 36 + 10 =
= 188
Bài 3: Tính
1 + 5 =
2 + 3 =
3 + 6 =
4 + 5 =
5 + 1 =
6 + 2 =
7 + 1 =
8 + 1 =
9 + 0 =
10 + 2=
11 + 2 =
1 + 3 =
2 + 6 =
3 + 7 =
4 + 2 =
5 + 2 =
6 + 3 =
7 + 3 =
8 + 2 =
9 + 1 =
10 + 0 =
11 + 3 =
1 + 4 =
2 + 8 =
3 + 2 =
4 + 1 =
5 + 4 =
6 + 4 =
7 + 2 =
8 + 0 =
9 + 2 =
10 + 6 =
11 + 6 =
Bài 4: Tính
6 - 2 =
3 - 1 =
4 - 2 =
5 - 2 =
8 - 5 =
10 - 6 =
4 - 3 =
3 - 3 =
5 - 1 =
2 - 2 =
3 - 1 =
4 - 1 =
2 - 1 =
4 - 3 =
5 - 0 =
9 - 4 =
8 - 6 =
7 - 3 =
8 - 4 =
7 - 6 =
9 - 5 =
7 - 7=
5 - 3 =
5 - 3=
6 - 3 =
7 - 3 =
7 - 6 =
6 - 5 =
9 - 7 =
9 - 3 =
8 - 8 =
8 - 0 =
5 - 3 =
Bài 5: Tính
6 - 2 =
5 + 2 =
9 - 5 =
2 + 0 =
8 + 2 =
4 - 4 =
7 - 3 =
3 + 6 =
7 + 2 =
9 - 5 =
3 + 6 =
1 + 5 =
7 - 6 =
7 + 1 =
3 + 5 =
2 - 1 =
6 + 3 =
5 + 2 =
9 - 4 =
6 + 4 =
4 + 2 =
6 + 1=
7 - 7=
4 + 3 =
7 + 3 =
5 - 2 =
6 - 5 =
8 - 6 =
6 - 4 =
7 - 3 =
10 + 0 =
5 +4 =
8 - 2 =
Tính:
a) -5/7(14/5 - 7/10) : |-2/3| - 3/4(8/9 + 16/3) + 10/3(1/3 + 1/5)
b) 17/-26(1/6 - 5/3) : 17/13 - 20/3(2/5 - 1/4) + 2/3(6/5 - 9/2)
c) -8/9(9/8 - 3/2) + 5/4 : (5/2 - 15/4) - 3/4(10/9 - 8/3) : (-1/3)
d) 21/10 : (12/5 - 9/10) . (-4/7) - 3/2(1/6 - 7/12) + 1/5(3/2 - 1/4)
a) Ta có: \(\dfrac{-5}{7}\left(\dfrac{14}{5}-\dfrac{7}{10}\right):\left|-\dfrac{2}{3}\right|-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)+\dfrac{10}{3}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)
\(=\dfrac{-5}{7}\cdot\dfrac{3}{2}\cdot\dfrac{21}{10}-\dfrac{3}{4}\cdot\dfrac{56}{3}+\dfrac{10}{3}\cdot\dfrac{8}{15}\)
\(=\dfrac{-9}{4}-14+\dfrac{16}{9}\)
\(=\dfrac{-1621}{126}\)
b) Ta có: \(\dfrac{17}{-26}\cdot\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)
\(=\dfrac{-17}{26}\cdot\dfrac{13}{17}\cdot\dfrac{-3}{2}-\dfrac{20}{3}\cdot\dfrac{3}{20}+\dfrac{2}{3}\cdot\dfrac{-33}{10}\)
\(=\dfrac{3}{4}-1-\dfrac{11}{5}\)
\(=-\dfrac{49}{20}\)
Tìm thương A:B, biết:
A= 9/1 + 8/2 + 7/3 + 6/4 + 5/5 + 4/6 + 3/7 + 2/8 + 1/9
B=1/2 + 1/3 + 1/4 + 1/5 + 1/6 + 1/7 + 1/8 + 1/9 + 1/10
\(A=\frac{9}{1}+\frac{8}{2}+\frac{7}{3}+\frac{6}{4}+\frac{5}{5}+\frac{4}{6}+\frac{3}{7}+\frac{2}{8}+\frac{1}{9}\)
\(=\left(9-1-1-...1\right)+\left(\frac{8}{2}+1\right)+\left(\frac{7}{3}+1\right)+...+\left(\frac{1}{9}+1\right)\)
\(=1+\frac{10}{2}+\frac{10}{3}+...+\frac{10}{9}=\frac{10}{2}+\frac{10}{3}+...+\frac{10}{9}+\frac{10}{10}\)
\(=10\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+\frac{1}{7}+\frac{1}{8}+\frac{1}{9}\right)=10B\)
vậy A:B=10
Viết số thích hợp vào chỗ chấm:
2 = … + 1 |
6 = … + 4 |
8 = 5 + … |
10 = … + 2 |
3 = … + 2 |
6 = 3 + … |
8 = … + 4 |
10 = 7 + … |
4 = 3 + … |
7 = 6 + … |
9 = 8 + … |
10 = … + 4 |
4 = … + 2 |
7 = 5 + … |
9 = 7 + … |
10 = 5 + … |
5 = 4 + … |
7 = … + 3 |
9 = 6 + … |
10 = 10 + … |
5 = … + 2 |
8 = 7 + … |
9 = …+ 4 |
10 = 0 + … |
6 = 5 + … |
8 = … + 2 |
10 = 9 + … |
1 = … + 1 |
Lời giải chi tiết:
2 = 1 + 1 |
6 = 2 + 4 |
8 = 5 + 3 |
10 = 8 + 2 |
3 = 1 + 2 |
6 = 3 + 3 |
8 = 4 + 4 |
10 = 7 + 3 |
4 = 3 + 1 |
7 = 6 + 1 |
9 = 8 + 1 |
10 = 6 + 4 |
4 = 2 + 2 |
7 = 5 + 2 |
9 = 7 + 2 |
10 = 5 + 5 |
5 = 4 + 1 |
7 = 4 + 3 |
9 = 6 + 3 |
10 = 10 + 0 |
5 = 3 + 2 |
8 = 7 + 1 |
9 = 5+ 4 |
10 = 0 + 10 |
6 = 5 + 1 |
8 = 6 + 2 |
10 = 9 + 1 |
1 = 0 + 1 |
2=1+1 6=2+4 8=5+3 10=8+2
3=1+2 6=3+3 8=4+4 10=7+3
4=3+1 7=6+1 9=8+1 10=6+4
4=2+2 7=5+2 9=7=2 10=5+5
5=4+1 7=4+3 9=6+3 10=10+0
5=3+2 8=7+1 9=5=4 10=0+10
6=5+1 8=6=2 10=9+1 1=0+1
cop hết mạng kìa
8/9÷3/7=
8/9+2/5=
7/8-1/3=
3/10×1/6=
b.hỗn số
1 2/7+6 5/6=
5 3/4-1/5 =
6 2/9÷4 7/10=
5/3+3/2-7/6=
\(\dfrac{8}{9}:\dfrac{3}{7}=\dfrac{56}{27}\\ \dfrac{8}{9}+\dfrac{2}{5}=\dfrac{58}{45}\\ \dfrac{7}{8}-\dfrac{1}{3}=\dfrac{13}{24}\\ \dfrac{3}{10}\times\dfrac{1}{6}=\dfrac{1}{20}\\ 1\dfrac{2}{7}+6\dfrac{5}{6}=\dfrac{9}{7}+\dfrac{41}{6}=\dfrac{341}{42}\\ 5\dfrac{3}{4}-\dfrac{1}{5}=\dfrac{23}{4}-\dfrac{1}{5}=\dfrac{111}{20}\\ 6\dfrac{2}{9}:4\dfrac{7}{10}=\dfrac{56}{9}:\dfrac{47}{10}=\dfrac{560}{423}\\ \dfrac{5}{3}+\dfrac{3}{2}-\dfrac{7}{6}=2\)