5/6+ 1/2 x 4/3

= 5/6+ 2/3

= 5/6+4/6

= 11/6

5/6- 3/8

= 20/24- 9/24

= 11/24

1)

2/5x3/4+3/4x3/5

= 3/10+9/20

=6/20+9/20

=3/4

2)

= 41/50-8/25

=41/50-16/50

=1/2

3)

=4/3-10/9

=12/9-10/9

=2/9

\(\dfrac{9}{10}\)

\(\dfrac{1}{24}\)

\(\dfrac{5}{2}\)

9/10

1/24

5/2

<=> x+1 + x+2 +x+ 3+ x+4 = 41

<=> 4x + 1+2+3+4 = 41

<=> 4x + 10=41 => 4x= 41-10 => 4x=31 x= 31/4

Đề này có gì sai ý bn, bn coi lại nhé

1: \(=\dfrac{1}{3}\cdot\dfrac{3}{7}\cdot\dfrac{1}{2}=\dfrac{1}{7\cdot2}=\dfrac{1}{14}\)

2: =5/12+1/7

=35/84+12/84=47/84

3: =8(8/9-6/9)

=8*2/9=16/9

4: \(=\dfrac{5}{12}\cdot\dfrac{12}{5}=1\)

5: =16/5+6

=16/5+30/5=46/5

6: =10*1/2-10*1/5

=5-2=3

Dây là câu 2a):

41+x=72

      x=72-41

      x=31

1. a) 76 x 34 + 86 x 34

   = 34 x ( 76 + 86 )

   = 34 x     162

   =    5508

   b) 1 x 3 + 1 x 4 + 1 x 7 + 1

   = 1 x 3 + 1 x 4 + 1 x 7 + 1 x 1

   = 1 x ( 3 + 4 + 7 + 1 )

   = 1 x     15

   =    15

help me

1/2 + 1/6 + 1/12 + 1/20 + 1/30 1/x = 41/42

5/6 + 1/x = 41/42

1/x = 41/42 - 5/6 

1/x = 1/7 

vậy x = 7

x = 7 ở vong 18 đúng không

bằng 7 dúng không

\(\frac{1}{x}=\frac{41}{42}-\frac{1}{30}-\frac{1}{20}-\frac{1}{12}-\frac{1}{6}-\frac{1}{2}\)

\(\frac{1}{x}=\frac{1}{7}=>x=7\)