(x-5).3/10=2000+5

(x-5).3/10=2005

x-5=2005:3/10

x-5=2005.10/3

x-5=20050/3

x=20050/3 +5

x=20065/3

\(\left(x-5\right)\)\(.\)\(\frac{30}{100}\)\(=\)\(20\times100+5\)

\(\left(x-5\right)\)\(.\)\(\frac{3}{10}\)\(=\)\(2005\)

\(\left(x-5\right)\)\(=\)\(2005\)\(\div\)\(\frac{3}{10}\)

\(\left(x-5\right)\)\(=\)\(2005\)\(.\)\(\frac{10}{3}\)

\(\left(x-5\right)\)\(=\)\(\frac{20050}{3}\)

\(x=\frac{20055}{3}\)

Hok tốt

\(\frac{4}{5}:\frac{x}{5}=\frac{20}{100}\)

       \(\frac{x}{5}=\frac{4}{5}:\frac{20}{100}\)

        \(\frac{x}{5}=4\)

        \(\Rightarrow x=4.5=20\)

2x + 20 + 20 = 100

2x + 40 = 100

2x = 100 - 40 = 60

x= 60: 2= 30

2 ( x + 10 ) + 20 = 100

2 ( x + 10 ) = 100 - 20

2 ( x + 10 ) = 80

( x + 10 ) = 80 : 2

x + 10 = 40

x = 40 - 10

x = 30

 Vậy x = 30

2 ( x + 10 ) + 20 = 100

2 ( x + 10 ) = 100 - 20

2 ( x + 10 ) = 80

( x + 10 ) = 80 : 2

x + 10 = 40

x = 40 - 10

x = 30

x + ( x + 10 ) + ( x + 20) + (x+ 30 ) + ... + ( x + 100 ) = 770

( x + x + x +... x) + ( 10 + 20 + 30 + ...... + 100) = 770

      X x 11    + 550 = 770

        X x 11 = 770 - 550

           X x 11 = 220 

              x      = 220 : 11

              x = 20

Ta phan tich :493=17.29

x se la uoc cua 493 va thoa man 20<x<100

Vay x la 29 

x=50

k mik nha

^_^

Học tốt

x-{150-[30+20.(100:20)]}=30

x={150-[30+20.5]}=30

x={150-[20+100]}=30

x={150-120}=30

x=30

Vậy x=30

x - { 150 - [30 + 20 . ( 100.20 )}} = 30

X = {150 - [30 + 20 . 5 ]} = 30

X= [150 - 130 ] = 30

X - 20 = 30 

x = 30 + 20 

X = 50

XONG RÙI K MÌNH NHA 

a) (125 - x) + 25 = 98

125 - x = 98 - 25

125 - x = 73

x = 125 - 73

x = 52

b) 100 : (x + 20) = 68 : 34

100 : (x + 20) = 2

x + 20 = 100 : 2

x + 20 = 50

x = 50 - 20

x = 30

c) (3x + 12) . 5 = 25 . 4 - 10

(3x + 12) . 5 = 100 - 10

(3x + 12) . 5 = 90

3x + 12 = 90 : 5

3x + 12 = 18

3x = 18 - 12

3x = 6

x = 6 : 2

x = 3

d) 210 : (2x - 3) - 20 = 10

210 : (2x - 3) = 10 + 20

210 : (2x - 3) = 30

2x - 3 = 210 : 30

2x - 3 = 70

2x = 70 + 3

2x = 73

x = 73/2

a, ( 125 - x ) + 25 = 98

⇒ 125 - x = 73

⇒ x = 52.

Vậy..

b, 100 : ( x + 20 ) = 68 : 34

⇒ 100 : ( x + 20 ) = 2

⇒ x + 20 = 50

⇒ x = 30

Vậy...

c, ( 3 . x + 12 ) . 5 = 25 . 4 - 10

⇒ ( 3 . x + 12 ) . 5 = 90

⇒ 3 .x + 12 = 18

⇒ 3x = 6

⇒ x = 2.

Vậy...

d, 210 : ( 2 .x - 3 ) - 20 = 10

⇒ ( 2 .x - 3 ) - 20 = 21

⇒ 2x - 3 = 41

⇒ 2x = 44

⇒ x = 22.

Vậy..

Cho mk chỉnh lại câu cuối:

 d, 210 : ( 2 .x - 3 ) - 20 = 10

⇒ 210 : ( 2 .x - 3 ) = 30

⇒ 2 . x - 3 = 7

⇒ 2x = 10

⇒ x = 5.

Vậy..