\(=>x\left(\dfrac{1}{2}+\dfrac{2}{3}\right)=\dfrac{10}{3}+1=\dfrac{13}{3}\)

\(=>x=\dfrac{13}{3}:\left(\dfrac{1}{2}+\dfrac{2}{3}\right)=\dfrac{13}{3}:\dfrac{7}{6}=\dfrac{26}{7}\)

5/6x - 1 = 10/3

5/6x = 10/3 + 1 = 13/3

X = 13/3 : 5/6 = 26/5

\(\dfrac{1}{2}\times x+\dfrac{2}{3}\times x-1=3\dfrac{1}{3}\)

\(\Rightarrow x\left(\dfrac{1}{2}+\dfrac{2}{3}\right)=\dfrac{10}{3}+1\)

\(\Rightarrow\dfrac{7}{6}x=\dfrac{13}{3}\)

\(\Rightarrow x=\dfrac{13}{3}:\dfrac{7}{6}\)

\(\Rightarrow x=\dfrac{26}{7}\)

Vô nghiệm

\(\dfrac{5}{7}\times x+\dfrac{2}{5}=\dfrac{2}{3}\\ \dfrac{5}{7}\times x=\dfrac{2}{3}-\dfrac{2}{5}=\dfrac{10}{15}-\dfrac{6}{15}=\dfrac{4}{15}\\ x=\dfrac{4}{15}:\dfrac{5}{7}=\dfrac{4\times7}{15\times5}=\dfrac{28}{75}\)

Vậy `x=28/75`

`HaNa☘D`

\(\dfrac{5}{7}\times x+\dfrac{2}{5}=\dfrac{2}{3}\)

\(\dfrac{5}{7}\times x=\dfrac{2}{3}-\dfrac{2}{5}\)

\(\dfrac{5}{7}\times x=\dfrac{10}{15}-\dfrac{6}{15}\)

\(\dfrac{5}{7}\times x=\dfrac{4}{15}\)

\(x=\dfrac{4}{15}:\dfrac{5}{7}\)

\(x=\dfrac{4}{15}\times\dfrac{7}{5}\)

\(x=\dfrac{28}{75}\)

#Toru

=>x*5/7=2/3-2/5=4/15

=>x=4/15:5/7=4/15*7/5=28/75

a. vô nghiệm  vì tổng hai số dương chỉ bằng ko khi chúng đồng thời bằng 0

b. tổng 3 số dưng =0 khi dồng thời cả 3 bằng 0

vậy x=1; y=-1; z=1

c.tổng 3 số dưng luông  lớn hơn bằng ko

vậy x=1/3; y=2; z=1

d tương tự 

x-z=0

x+y=0

z+1/4=0

.............

z=-1/4

x=-1/4

y=1/4

Cac ban lam chi tiet giup minh voi 

\(\left(-x^3.z.y\right).\left(\dfrac{2}{3}.y.x^2\right)^2\)

\(=-x^3.z.y.\dfrac{4}{9}.y^2.x^4\)

\(=-\dfrac{4}{9}x^7.y^3.z\)

`(-x^3zy)(2/3yx^2)^2`

`=-4/9x^3zy.y^2x^4`

`=-4/9x^{3+4}.y^{1+2}z`

`=-4/9x^7y^3z`

\(\left(-x^3zy\right)\left(\dfrac{2}{3}yx^2\right)^2\)

\(\Leftrightarrow\left(-x^3yz\right)\left(\dfrac{2}{3}x^2y\right)\left(\dfrac{2}{3}x^2y\right)\)

\(\Leftrightarrow-\left[x^7y^3z\left(\dfrac{2}{3}\right)^2\right]\)

\(\Leftrightarrow-\dfrac{4}{9}x^7y^3z\)