1)
[tex]\frac{15}{25} = \frac{45}{x}\\15x = 45 \cdot 25\\15x = 1125\\x = 75[/tex]
2)
[tex]\frac{6}{25} = \frac{x}{30} \\25x = 30 \cdot 6\\25x = 180\\x = \frac{36}{5}[/tex]
3)
[tex]\frac{2.5}{6} = \frac{x}{9}\\6x = 2.5 \cdot 9\\6x = 22.5\\x = 3.75[/tex]
4)
[tex]\frac{6}{7} = \frac{x}{40}\\7x = 40 \cdot 6\\7x = 240\\x = \frac{240}{7}[/tex]
