1.
a) 2 $\frac{1}{3}$ = $\frac{2x3+1}{3}$ = 2 $\frac{7}{3}$
b) 4 $\frac{2}{5}$ = $\frac{2x4+5}{5}$ = $\frac{22}{5}$
c) 3 $\frac{1}{4}$ = $\frac{3x4+1}{4}$ = $\frac{13}{4}$
2.
a) 2 $\frac{1}{3}$ + 4 $\frac{1}{3}$ = $\frac{7}{3}$ + $\frac{13}{3}$ = $\frac{20}{3}$
b) 10 $\frac{3}{10}$ - 4 $\frac{7}{10}$ = $\frac{103}{10}$ - $\frac{47}{10}$ = $\frac{56}{10}$ = $\frac{28}{5}$
3.
a) 2 $\frac{1}{3}$ x 5 $\frac{1}{4}$ = $\frac{7}{3}$ x $\frac{21}{4}$ = $\frac{49}{4}$
b) 8 $\frac{1}{6}$ : 2 $\frac{1}{2}$ = $\frac{49}{6}$ : $\frac{5}{2}$ = $\frac{49}{15}$
4.
Đáp án: C