Question

Tìm x, y, z, biết :

3x = 2y ; 7y =5z và x - y + z =32

Answer 1

3x = 2y ; 7y =5z

=> \(\frac{x}{2}=\frac{y}{3};\frac{y}{5}=\frac{z}{7}\)

=>  \(\frac{x}{10}=\frac{y}{15};\frac{y}{15}=\frac{z}{21}\)

=> \(\frac{x}{10}=\frac{y}{15}=\frac{z}{21}=\frac{x-y+z}{10-15+21}=\frac{32}{16}=2\)

=> x=2.10=20

y=2.15=30

z=2.21=42