[tex]1.\rightarrow \frac{2}{3}=\frac{6}{x}\\\\2x=18\\\\x=\frac{18}{2}\\\\x=9\\\\2.\rightarrow \frac{4}{7}=\frac{x}{42}\\\\7x=42 \times 4\\\\x=\frac{168}{7}\\\\x=24\\\\3.\rightarrow \frac{2x}{48}=\frac{3}{12}\\\\\frac{x}{24}=\frac{1}{4}\\\\x=\frac{24}{4}\\\\x=6\\\\4.\rightarrow \frac{12}{15}=\frac{x}{20}\\\\\frac{4}{5}=\frac{x}{20}\\\\5x=80\\\\x=\frac{80}{5}\\\\x=16[/tex]
