/x+4/15/-/-3,75/=-/-2,15/

/x+4/15/-15/4=-\(\frac{43}{20}\)

x+4/15=\(\frac{43}{20}+\frac{15}{4}\)

x+4/15=59/10

    x=59/10-4/15

    x=\(5\frac{19}{30}\)

| x + 4/15 | - | - 3,75 | = - | - 2,15 |

| x + 4/15 | - 3,75      = - 2,15

| x + 4/15 |               = - 2,15 + 3,75

| x + 4/15 |               = 1,6

Trường hợp 1 :  x + 4/15 = 1,6   suy ra x = 4/3

Trương hợp 2:  x + 4/15 = - 1,6 suy ra x = -28/15

b) | x + 415 | - | -3,75| = -(-2,15)

\(\left|x+\frac{4}{15}\right|-\left|-3,75\right|=-\left|-2,15\right|\)

\(\Rightarrow\left|x+\frac{4}{15}\right|-3,75=-2,15\)

\(\Rightarrow\left|x+\frac{4}{15}\right|=-2,15+3,75\)

\(\Rightarrow\left|x+\frac{4}{15}\right|=1,6\)

\(\Rightarrow\left|x+\frac{4}{15}\right|=\frac{8}{5}\)

\(\Rightarrow\left[\begin{array}{nghiempt}x+\frac{4}{15}=\frac{8}{5}\\x+\frac{4}{15}=-\frac{8}{5}\end{array}\right.\)

\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{4}{3}\\x=-\frac{28}{15}\end{array}\right.\)

Ta có : \(\left|x+\frac{4}{15}\right|-\left|-3,75\right|=-\left|-2,15\right|\)

\(\Leftrightarrow\left|x+\frac{4}{15}\right|=3,75-2,15=\frac{8}{5}\)

\(\Rightarrow\left[\begin{array}{nghiempt}x+\frac{4}{15}=\frac{8}{5}\\-x-\frac{4}{15}=\frac{8}{5}\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=\frac{4}{3}\\x=-\frac{28}{15}\end{array}\right.\)

\(\dfrac{7011}{25}:\left(x-42.6\right).15=13\)

\(\Rightarrow\dfrac{7011}{\dfrac{25}{\left(x-42,6\right)}}.0,15=13\)

\(\Rightarrow\dfrac{280,44}{\left(x-42,6\right)}.0,15=13\)

\(x-\left(280,44-42,6\right)\)

\(x=237.8+86,7\)

\(x=324,54\)

\(\)Vậy x=324,54

b.

\(7,2-\left(x+3,75:2,1\right):1,9=5,2\)

\(\Rightarrow7,2+\dfrac{-\left(x-\dfrac{3,75}{2,1}\right)}{1,9}=5,2\)

\(7,2+\dfrac{-\left(x-1,8\right)}{1,9}=5,2\)

|x+4/15|-|-3,75|=-|-2,15|

|x+4/15|-3,75=-2,15

|x+4/15|=-2,15+3,75

|x+4/15|= 1,6 hoặc -1,6

Với x+4/15= 1,6 => x = 1,6-4/15 = 4/3

Với x+4/15= -1,6 => x = -1,6-4/15= -28/15

Vậy x= 4/3 hoặc x = -28/15

/x + \(\frac{4}{15}\)/ - 3,75 = -2,15

=> /x + \(\frac{4}{15}\)/ = 1,6

=> \(x+\frac{4}{5}=1,6\) hoặc \(x+\frac{4}{5}=-1,6\)

=> \(x=0,8\)hoặc \(x=-2,4\)

c) 22/5 + 51/9 + 11/4 + 3/5 + 1/3 + 1/4
= 22/5 +3/5 +51/9 + 1/3 +11/4+1/4
= (22/5 +3/5) +(51/9 + 3/9) +(11/4+1/4)
= 25/5 +54/9 +12/4
= 5 +6 +3
= 14
d) (1/6 + 1/10 + 1/15) : (1/6 + 1/10 - 1/15) 
= (5/30 + 3/30 +2/30 ) :(5/30 +3/30 -2/30)
= 10/30 : 6/30
= 1/3 : 1/5
= 5/3

a)|x+4/15|-3,75=-2,15

|x+4/15|=-2,15+3/75

|x+4/15|=1,6

=>x+4/15=1,6 hoặc x+4/15=-1,6

x=1,6-4/15              x=-1,6-4/15

x=4/3                      x=-28/15

b)|x-5/3|<1/3

*)x-5/3<1/3

x<1/3+5/3=6/3

x<2

*)x-5/3<-1/3

x<-1/3+5/3

x<4/3

=>x<4/3

Vậy x<4/3

\(\left|x+\frac{4}{15}\right|-\left|-3,75\right|=-\left|-2,15\right|\)

\(\left|x+\frac{4}{15}\right|-3,75=-2,15\)

\(\left|x+\frac{4}{15}\right|=-2,15+3,75\)

\(\left|x+\frac{4}{15}\right|=1,6\)

Ta có 2 trường hợp

trường hợp 1

\(x+\frac{4}{15}=1,6\)

\(x=1,6-\frac{4}{15}\)

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

Trường hợp 2

\(x+\frac{4}{15}=-1,6\)

\(x=-1,6-\frac{4}{15}\)

\(x=\frac{-28}{15}\)

Vậy \(x=\left\{-\frac{28}{15};\frac{4}{3}\right\}\)

=>3,75x=3,75x2,1

=>x=2,1

2,1 x 3,75 =X x (0,05+3,7)

2,1 x 3,75 =X x 3,75

X x 3,75 = 2,1 x 3,75

X x 3,75 = 7,875

           X = 7,875 : 3,75

           X = 2,1