\(a)\) \(\left|x\right|=\left|x+2\right|=3\)

\(\text{Trường hợp 1:}\)

\(\Leftrightarrow x+x+2=3\)

\(\Leftrightarrow2x=1\)

\(\Leftrightarrow x=\frac{1}{2}\)

\(\text{Trường hợp 2:}\)

\(\Leftrightarrow-x-x-2=3\)

\(\Leftrightarrow-2x=5\)

\(\Leftrightarrow x=-\frac{5}{2}\)

\(b)\) \([\frac{12}{25}.\left(0,75+\frac{7}{4}\right)-1].x=[\frac{7}{5}-\frac{3}{25}.\left(10,6-\frac{3}{5}\right)]\)

\(\Leftrightarrow[\frac{12}{25}.2,5-1].x=[\frac{7}{5}-\frac{3}{25}.10]\)

\(\Leftrightarrow[1,2-1].x=[\frac{7}{5}-2]\)

\(\Leftrightarrow0,2.x=-\frac{3}{5}\)

\(\Leftrightarrow x=-\frac{3}{5}:0,2\)

\(\Leftrightarrow x-3\)

a)

x × 1 1 2 = 1 4 5 − 2 5 x × 3 2 = 9 5 − 2 5 x × 3 2 = 7 5 x = 7 5 : 3 2 x = 14 15

b)

x × 0 , 75 + x × 0 , 25 = 5 x × 0 , 75 + 0 , 25 = 5 x × 1 = 5 x = 5 : 1 x = 5

1) 2,75 - 5/6 × 2/5 = 2,75 - (5/6) × (2/5) = 2,75 - 1/3 = 2,75 - 0,33 = 2,42

2) 1,25 - (5/6 - 0,75) - 3/5 = 1,25 - (5/6 - 0,75) - 3/5 = 1,25 - (5/6 - 3/4) - 3/5 = 1,25 - (5/6 - 9/12) - 3/5 = 1,25 - (10/12 - 9/12) - 3/5 = 1,25 - 1/12 - 3/5 = 1,25 - 0,08 - 0,6 = 1,25 - 0,68 = 0,57

3) 4/9 × 0,75 + 8/5 + 3,125 = (4/9) × 0,75 + 8/5 + 3,125 = 0,44 + 8/5 + 3,125 = 0,44 + 1,6 + 3,125 = 0,44 + 4,725 = 5,165

4) 1,125 - 4/7 - 0,12 = 1,125 - (4/7) - 0,12 = 1,125 - 0,57 - 0,12 = 0,435 - 0,12 = 0,315

5) (1/3 + 0,4) × 3,5 + (1/6 + 0,75) × 6/5

     [Giải:]

107 + ( 210 + x ) = 317

210 + x = 317 - 107

210 + x = 210

x = 210 - 210

x = 0

2x + (0,5 + 25%) = 0,75

2x + (0,5 + 0,25) = 0,75

2x + 0,75 = 0,75

2x = 0,75 - 0,75

2x = 0

x = 0 : 2

x = 0

4221 : (x - 16 ) = 21

x - 16 = 4221 : 21

x - 16 = 201

x = 201 + 16

x = 217

50% + 0,75x = 0,5

0,5 + 0,75x = 0,5

0,75x = 0,5 - 0,5

0,75x = 0

x = 0 : 0,75

x = 0 

 | - Câu khác làm tương tự - |

          [ Hoq chắc ]

a, 107 + ( 210 - x ) = 317

210 - x = 317 - 107

210 - x = 210

x = 210 - 210

x = 0

Vậy x = 0

b, 2x + ( 0,5 + 25% ) = 0,75

2x + 0,75 = 0,75

2x = 0,75 - 0,75

2x = 0

x = 0

Vậy x = 0

c, 4221 : ( x - 16 ) = 21

x - 16 = 4221 : 21

x - 16 = 201

x = 201 + 16

x = 217

Vậy x = 217

d, 156 - ( x + 61 ) = 21

x + 61 = 156 - 21

x + 61 = 135

x = 135 - 61

x = 74

Vậy x = 74

e, ( 235 - x ) - 81 = 54

235 - x = 54 + 81

235 - x = 135

x = 235 - 135

x = 100

Vậy x = 100

f, 50% + 0,75. x = 0,5

0,75. x = 0,5 - 50%

0,75. x = 0

x = 0

Vậy x = 0

107+(210-x)=317

210-x=317-107

210-x=210

x=210-210

x=0

2x+(0,5+25%)=0,75

2x+(0,5+0,25)=0,75

2x+ 0,75=0,75

2x=0,75-0,75

2x=0

x=0

4221:(x-16)=21

x-16=4221:21

x-16=201

x=201+16

x=217

156-(x+61)=21

x+61=156-21

x+61=135

x=135-61=74

(235-x)-81=54

235-x=54+81

235-x=135

x=235-135=100

50%+0,75.x=0,5

0,5+0,75.x=0,5

0,75.x=0

x=0

em oi bai ni anh chiu em a co chi em hoi ai nhe

\(\frac{3}{4}:\frac{x}{6}=0.75\)

\(\frac{3}{4}\cdot\frac{6}{x}=\frac{3}{4}\)

\(\frac{6}{x}=\frac{3}{4}:\frac{3}{4}\)

\(\frac{6}{x}=1\)

\(x=6\)

3/4 : x/6 = 0,75

        x/6 = 0,75 : 0,75 

        x/6 = 1 

        x   = 6

Hok tốt !!! 

                                                                                 ~~~ Mon ~~~

\(\frac{3}{4}:\frac{x}{6}=0,75\)

\(\frac{3}{4}:\frac{x}{6}=\frac{3}{4}\)

\(\frac{x}{6}=\frac{3}{4}:\frac{3}{4}\)

\(x:6=1\)

\(x=1x6\)

\(x=6\)

Vậy x = 6