\(\frac{6}{15}= \frac{6\div3}{15\div3}= \frac{2}{5}\)
\(\frac{6}{15}=\frac{6\cdot2}{15\cdot2}= \frac{12}{30}\)
\(\frac{6}{15}=\frac{6\div100}{15\div100}= \frac{600}{1500}\)
To obtain an equivalent fraction, you have to multiply or simplify that fraction.