the festival in school

the festival in the park 

.....

$$\begin{gathered} (2x-3).7=(x+1).4 \\ 14x-21=4x+4 \\ 14x-4x=21+4 \\ 10x=25 \\ x=\frac{25}{10} \\ x=\frac{5}{2} \end{gathered}$$

Vậy $x=\frac{5}{2}$

ta có 

$\frac{3x}{15}=\frac{2y}{32}=\frac{z}{17}$

áp dụng tính chất dãy tỉ số bằng nhau ta có 

$\frac{3x}{15}=\frac{2y}{32}=\frac{z}{17}=\frac{3x-2y}{15-32}=\frac{47}{-17}$

ta có 

$$\begin{gathered} \frac{x}{5}=\frac{47}{-17}\Rightarrow x=\frac{-235}{17} \\ \frac{y}{16}=\frac{47}{-17}\Rightarrow y=\frac{-752}{17} \\ \frac{z}{17}=\frac{47}{-17}\Rightarrow z=-47 \end{gathered}$$

=2