a) 11/6 and b) 5/21.
To solve this problem we have to do fraction operations. To sum and substrac fractions with different denominators with use the following formula [tex]\frac{a}{b} +\frac{c}{d} = \frac{a.d+b.c}{b.d}[/tex] for the sum and [tex]\frac{a}{b} -\frac{c}{d} = \frac{a.d-b.c}{b.d}[/tex] for the difference.
a) [tex]\frac{3}{4} +\frac{5}{6} = \frac{(3)(6)+(4)(5)}{(4)(6)}=\frac{24+20}{24}=\frac{44}{24}= \frac{11}{6}[/tex]
b) [tex]\frac{4}{7}-\frac{1}{3} = \frac{(4)(3) - (7)(1)}{(7)(3)}=\frac{12-7}{21}= \frac{5}{21}[/tex]
