A: [tex]1- \frac{1}{2} ( \frac{9}{12} - \frac{4}{12} )= 1- \frac{1}{2} * \frac{5}{12} =1- \frac{5}{24} = \frac{24}{24} - \frac{5}{24} = \frac{19}{24} [/tex]
B: [tex] \frac{\frac{24}{12} - \frac{4}{12} - \frac{1}{12} }{ \frac{60}{12}- \frac{3}{12} - \frac{8}{12} } = \frac{ \frac{19}{12} }{ \frac{49}{12} } = \frac{19}{12} * \frac{12}{49} = \frac{19}{49} [/tex]