Question

Дроби: а) 4/9,5/6,7/2 к знаменателю 18 б) дроби: 7/8,5/16,21/40 к знаменателю 80

Answer 1

А)4/9=8/18
5/6=15/18
7/2=63/18
б) 7/8=70/80
5/16=25/80
21/40=42/80

Answer 2

$a) \frac{4}{9}= \frac{4\cdot2}{9\cdot2}= \frac{8}{18} \\ \\ \frac{5}{6}= \frac{5\cdot3}{6\cdot3}= \frac{15}{18} \\ \\ \frac{7}{2}= \frac{7\cdot9}{2\cdot9}= \frac{63}{18} \\ \\ b) \frac{7}{8}= \frac{7\cdot10}{8\cdot10}= \frac{70}{80} \\ \\ \frac{5}{16}= \frac{5\cdot5}{16\cdot5}= \frac{25}{80} \\ \\ \frac{21}{40}= \frac{21\cdot2}{40\cdot2}= \frac{42}{80}$