Question

3 3/4•6/7-11/21•3 3/4​

Answer 1

$1)3 \frac{3}{4} \times \frac{6}{7} = \frac{3 + 3 \times 4}{4} \times \frac{6}{7} = \frac{15}{4} \times \frac{6}{7} = \frac{15 \times 6}{4 \times 7} = \frac{90}{28} = \frac{45 \times 2}{14 \times 2} = \frac{45}{14} = \frac{3 \times 14 + 3}{14} = 3 \frac{3}{14}$

$2) \frac{11}{21} \times 3 \frac{3}{4} = \frac{11}{21} \times \frac{3 + 3 \times 4}{4} = \frac{11}{21} \times \frac{15}{4} = \frac{11 \times 15}{21 \times 4} = \frac{165}{84} = \frac{55 \times 3}{28 \times 3} = \frac{55}{28} = \frac{1 \times 28 + 27}{28} = 1 \frac{27}{28}$

$3) 3\frac{3}{14} - 1 \frac{27}{28} = \frac{3 + 3 \times 14}{14} - \frac{27 + 1 \times 28}{28} = \frac{45}{14} - \frac{55}{28} = \frac{45 \times 2}{14 \times 2} - \frac{55 \times 1}{28 \times 1} = \frac{90}{28} - \frac{55}{28} = \frac{90 - 55}{28} = \frac{35}{28} = \frac{5 \times 7}{4 \times 7} = \frac{5}{4} = \frac{1 \times 4 + 1}{4} =1 \frac{1}{4}$