[tex]a) \frac{12}{28} = \frac{12 \div 4}{28 \div 4} = \frac{3}{7} [/tex]
[tex]b) \frac{48}{64} = \frac{48 \div 16}{64 \div 16} = \frac{3}{4} [/tex]
[tex]c) \frac{36}{240} = \frac{36 \div 12}{240 \div 12} = \frac{3}{20} [/tex]
[tex]d) \frac{120}{25} = \frac{120 \div 5}{25 \div 5} = \frac{24}{5} [/tex]
[tex]e) \frac{20}{35} = \frac{20 \div 5}{35 \div 5} = \frac{4}{7} [/tex]
[tex]f) \frac{81}{18} = \frac{81 \div 9}{18 \div 9} = \frac{9}{2} [/tex]
