Số cần tìm là:

1+2+3+4+5+6+7+8+9x4:2+99+1=163

Đs:163

đung 100%

Tổng Trên là : 154

1+2+3+4+5+6+7+8+9x4:2+99+1

=1+2+3+4+5+6+7+8+36:2+99+1

=1+2+3+4+5+6+7+8+18+99+1

=154

\(\frac{4}{9}\cdot\frac{11}{15}+\frac{4}{9}\cdot\frac{4}{15}\)

\(=\frac{4}{9}\left(\frac{11}{15}+\frac{4}{15}\right)\)

\(=\frac{4}{9}\cdot1=\frac{4}{9}\)

\(\left(x-\frac{2}{3}\right).\frac{1}{6}=\frac{1}{8}\)

\(\left(x-\frac{2}{3}\right)=\frac{3}{4}\)

\(x=\frac{17}{12}\)

\(\left(x-\frac{2}{3}\right)\cdot\frac{1}{6}=18\)

\(\Rightarrow x-\frac{2}{3}=18:\frac{1}{6}=108\)

\(\Rightarrow x=108+\frac{2}{3}=\frac{326}{3}\)

\(\Rightarrow x=\frac{326}{3}\)

\(\frac{1}{3}+\frac{2}{3}\cdot x=\frac{2}{5}\)

\(\Rightarrow\frac{2}{3}\cdot x=\frac{2}{5}-\frac{1}{3}=\frac{1}{15}\)

\(\Rightarrow x=\frac{1}{15}:\frac{2}{3}=\frac{1}{10}\)

\(\Rightarrow x=0,1\)

a) \(1678\cdot24+77\cdot1678-1678=1678\left(24+77-1\right)=167800\)

b) Ta có: \(\dfrac{2}{5}+\dfrac{4}{11}+\dfrac{3}{5}+\dfrac{18}{11}+\dfrac{1}{4}+\dfrac{1}{6}\)

\(=\left(\dfrac{2}{5}+\dfrac{3}{5}\right)+\left(\dfrac{4}{11}+\dfrac{18}{11}\right)+\dfrac{1}{4}+\dfrac{1}{6}\)

\(=3+\dfrac{1}{4}+\dfrac{1}{6}\)

\(=\dfrac{36}{12}+\dfrac{3}{12}+\dfrac{2}{12}=\dfrac{41}{12}\)

c) \(\dfrac{7}{9\cdot7}+\dfrac{7}{9\cdot4}-\dfrac{7}{9\cdot10}\)

\(=\dfrac{7}{9}\left(\dfrac{1}{7}+\dfrac{1}{4}-\dfrac{1}{10}\right)\)

\(=\dfrac{7}{9}\cdot\left(\dfrac{20}{140}+\dfrac{35}{140}-\dfrac{14}{140}\right)\)

\(=\dfrac{7}{9}\cdot\dfrac{41}{140}=\dfrac{41}{180}\)

khó quá mk giải miết mà không ra

khó vãi

\(\frac{6}{5}-\frac{1}{4}+\frac{4}{5}-\frac{3}{4}\)

\(=\left(\frac{6}{5}+\frac{4}{5}\right)-\left(\frac{1}{4}+\frac{3}{4}\right)\)

\(=2-1\)

\(=1\)

\(\frac{7}{9}-\frac{5}{12}+\frac{2}{9}-\frac{7}{12}\)

\(=\left(\frac{7}{9}+\frac{2}{9}\right)-\left(\frac{5}{12}+\frac{7}{12}\right)\)

\(=1-1\)

\(=0\)

các câu sau tương tự

A=1

B=0

C=ÂM 8/15

D=0

E=2

F=3/2

H=2/3 

LẦN SAU CHO KHÓ SÍU NHA LỚP 5 CŨNG LÀM ĐC

=2/3.9/7.4/15+5/7

=6/7.4/15+5/7

=8/35+5/7

=8/35+25/35

=33/35

\(\dfrac{2}{3}:\dfrac{7}{9}\times\dfrac{4}{15}+\dfrac{5}{7}=\dfrac{6}{7}\times\dfrac{4}{15}+\dfrac{5}{7}=\dfrac{8}{35}+\dfrac{5}{7}=\dfrac{33}{35}\)

2/3:7/9x4/15+5/7

\(=\dfrac{2}{3}\times\dfrac{9}{7}\times\dfrac{4}{15}+\dfrac{5}{7}\)

=\(\dfrac{2.9.4}{3.7.15}+\dfrac{5}{7}\)

\(=\dfrac{8}{35}+\dfrac{5}{7}\)

\(=\dfrac{8}{35}+\dfrac{25}{35}\)

\(=\dfrac{33}{35}\)

`4/7+4`

`=4/7+4/1`

`=4/7+28/7`

`=32/7`

__

`3+6/11`

`=33/11+6/11`

`=39/11`

__

`3-5/7`

`=3/1-5/7`

`=21/7-5/7`

`=16/7`

__

`21/9-2`

`=21/9-18/9`

`=3/9`

`=1/3`

__

`15/24+2`

`=15/24+48/24`

`=63/24`

`=21/16`

__

`63/45-20/25`

`=63/45-4/5`

`=63/45-36/45`

`=27/45`

`=9/15`

__

`3/4-2/8`

`=3/4-1/4`

`=2/4`

__

`6/7-5/8`

`=48/56-35/56`

`=13/56`

__

`37/45-5/9`

`=37/45-25/45`

`=12/45`

`=4/15`

__

`46/39-11/13`

`=46/39-33/39`

`=13/39`

`=1/2`

__

`5/12+3/4+1/3`

`=5/12+9/12+4/12`

`=14/12+4/12`

`=18/12`

`=3/2`

__

`1/2+3/7+11/14`

`=7/14+6/14+11/14`

`=13/14+11/14`

`=24/14`

`=12/7`

__

`7/10-(1/5+1/4)`

`=7/10-(4/20+5/20)`

`=7/10-9/20`

`=14/20-9/20`

`=5/20`

`=1/4`

__

`15/4-2/3-3/4`

`=(15/4-3/4)-2/3`

`=12/4-2/3`

`=3-2/3`

`=9/3-2/3`

`=7/3`

a. 60x17/20=51

b.5/6x12/35=2/7

c.1/9

a) 60 x 17/20= 51

b) 5/6 x 12/35 = 2/7

c) 1/9

1x2x3x4x5x6x7x8x9

2x3x4x5x6x7x8x9x10

=1/10

b)1/2*2/3*3/4*4/5*5/6*6/7*7/8*8/9*9/10

=1x2x3x4x5x6x7x8x9

  2x3x4x5x6x7x8x9x10

= 1

  10