Question

Tìm x,y,z biết:

x/2 = y/3 ; x/4=z/5 và x+y+z =45

Answer 1

\(\frac{x}{2}=\frac{y}{3}\Rightarrow\frac{x}{4}=\frac{y}{6}\) 

\(\frac{x}{4}=\frac{z}{5}\)

\(\Rightarrow\frac{x}{4}=\frac{y}{6}=\frac{z}{5}\)

\(\Rightarrow\frac{x+y+z}{4+5+6}=\frac{x}{4}=\frac{y}{6}=\frac{z}{5}\) mà x + y + z = 45

\(\Rightarrow\frac{45}{15}=\frac{x}{4}=\frac{y}{6}=\frac{z}{5}\)

\(\Rightarrow3=\frac{x}{4}=\frac{y}{6}=\frac{z}{5}\)

\(\Rightarrow\hept{\begin{cases}x=3\cdot4=12\\y=3\cdot6=18\\z=3\cdot5=15\end{cases}}\)

Answer 2

Noob vl