\(\frac{42}{y}=\frac{18}{21}\)
\(\Rightarrow y\times18=42\times21\)
\(\Rightarrow y\times18=882\)
\(\Rightarrow y=882:18\)
\(\Rightarrow y=49\)
Vậy \(y=49\)
\(\frac{y}{14}=\frac{25}{35}\)
\(\Rightarrow y\times35=25\times14\)
\(\Rightarrow y\times35=350\)
\(\Rightarrow y=350:35\)
\(\Rightarrow y=10\)
Vậy \(y=10\)
a,\(\frac{42}{y}=\frac{18}{21}\)=> \(18y=882=>y=49\)
b,\(\frac{y}{14}=\frac{25}{35}< =>\frac{y}{14}=\frac{5}{7}=>7y=70=>y=10\)
