Đặt: \(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=k\Rightarrow x=2k;y=3k;z=5k\)

Có: xyz=810

\(\Leftrightarrow2k\cdot3k\cdot5k=810\)

\(\Leftrightarrow k^3=27\)

\(\Leftrightarrow k=3\)

=>\(\begin{cases}x=2k=2\cdot3=6\\y=3k=3\cdot3=9\\z=5k=5\cdot3=15\end{cases}\)

Ta có: \(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}\)

\(\Rightarrow\left(\frac{x}{2}\right)^3=\frac{x}{2}\cdot\frac{x}{2}\cdot\frac{x}{2}=\frac{x}{2}=\frac{y}{3}=\frac{z}{5}\)

\(\Rightarrow\frac{x.y.z}{30}=\frac{810}{30}=27\)

\(\Rightarrow\left(\frac{x}{8}\right)^3=27\)

\(\Rightarrow x^3=8\cdot27=216\)

\(\Rightarrow x=6\)

Với x = 6 \(\Rightarrow\begin{cases}\frac{6}{2}=\frac{y}{3}\Rightarrow y=\frac{6\cdot3}{2}=9\\\frac{6}{2}=\frac{z}{5}\Rightarrow x=\frac{6\cdot5}{2}=15\end{cases}\)

Với x = 6 thì bạn tự tính z theo cách tt

sorry, y = 9 còn z = 12, bn tự tính x

đặt x\2=y\3=z\5=k

=>x=2k

y=3k

z=5k

thay x=2k;y=3k;z=5k vào x.y.z=810 ta được:

2k.3k.5k=810

30k³=810

k³=27

k³=3³

=>k=3

=>x=2.3=6

y=3.3=9

z=5.3=15

Nguyễn Trần Khánh Linh sai

trieu dang kb vs mik nhá giỏi ghêk

b) \(x:y:z=2:3:5\Rightarrow\frac{x}{2}=\frac{y}{3}=\frac{z}{5}\)

Đặt \(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=k\Rightarrow\hept{\begin{cases}x=2k\\y=3k\\z=5k\end{cases}}\)

\(x.y.z=810\Rightarrow2k.3k.5k=810\Rightarrow30k^3=810\Rightarrow k^3=27\Rightarrow k=3\)

\(\Rightarrow\hept{\begin{cases}x=6\\y=9\\z=15\end{cases}}\)

x=6

y=9

z=15

b , (x,y,z)= (6,9,15)

đặt x/2 = y/3 = z/5 = k

=> x = 2k ; y = 3k ; z = 5k

vì xyz = 810

hay 2k . 3k . 5k = 810

30k³ = 810

k³ = 27

=> k = 3

Từ đó suy ra : a = 6 ; b = 9 ; z = 15

Vậy ...

Gọi \(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=k\)

\(\Rightarrow x=2k;y=3k;z=5k\)

\(\Rightarrow x.y.z=2k.3k.5k=810\)

\(\Rightarrow30k^3=810\)

\(\Rightarrow k^3=27\)

\(\Rightarrow k=3\)

\(\Rightarrow x=3.2=6\)

      \(y=3.3=9\)

      \(z=3.5=15\)

Vậy x = 6; y = 9; z = 15

ta có: x/2=y/3=z/5

x*y*z=810

=> x/2=y/3=z/5=x*y*z/2*3*5=810/30=27

x/2=27=> x=27*2=54

y/3=27=> y=27*3=81

z/5=27=> z=27*5=135

vậy x=54

y=81

z=135

a) 3x = 2y \(\Rightarrow\)\(\frac{x}{2}=\frac{y}{3}\)\(\Rightarrow\frac{x}{2}.\frac{1}{5}=\frac{y}{3}.\frac{1}{5}\)\(\Rightarrow\frac{x}{10}=\frac{y}{15}\)

\(7y=5z\Rightarrow\frac{y}{5}=\frac{z}{7}\Rightarrow\frac{y}{5}.\frac{1}{3}=\frac{z}{7}.\frac{1}{3}\Rightarrow\frac{y}{15}=\frac{z}{15}\)

\(\Rightarrow\frac{x}{10}=\frac{y}{15}=\frac{z}{21}\Rightarrow\frac{x+y+z}{10+15+21}=\frac{32}{46}=\frac{2}{3}\)

\(\hept{\begin{cases}x=10.\frac{2}{3}=\frac{20}{3}\\y=15.\frac{2}{3}=10\\z=21.\frac{2}{3}=14\end{cases}}\)

Vậy \(\hept{\begin{cases}x=10.\frac{2}{3}=\frac{20}{3}\\y=15.\frac{2}{3}=10\\z=21.\frac{2}{3}=14\end{cases}}\)

\(\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=\frac{x.y.z}{2.3.5}=\frac{810}{30}=27\)

\(\Rightarrow\frac{x}{2}=27\Leftrightarrow x=27.2=54\)

\(\Rightarrow\frac{y}{3}=27\Leftrightarrow y=27.3=81\)

\(\Rightarrow\frac{z}{5}=27\Leftrightarrow z=27.5=135\)

Vậy x = 54 ; y = 81 ; z = 135

Ta có: x/2=y/3=z/5=a (a khác 0)

Suy ra: x=2a;y=3a;z=5a

Suy ra:x*y*z=2a*3a*5a=2*3*5*a*a*a=30a³=810

Suy ra:a³=810:30=27.

Suy ra:a=3

Suy ra: x=3*2=6

          y=3*3=9

          z=3*5=15