Question

Сравните дроби с разными знаменателями в) 2/9+3/8 е) 5/12+4/15 и) 7/37+5/51 м)9/180+7/120 подробности /-дробь

Answer 1

В)
$\frac{2}{9} +\frac{3}{8} = \frac{2*8}{9*8}+ \frac{3*9}{8*9}= \frac{16}{72}+ \frac{27}{72} = \frac{43}{72} \\ \\ \frac{2}{9} \ \textless \ \frac{3}{8} \\$

е)
$\frac{5}{12}+ \frac{4}{15}= \frac{5*5}{12*5} + \frac{4*4}{15*4} = \frac{25+16}{60} = \frac{41}{60} \\ \\ \frac{5}{12} \ \textgreater \ \frac{4}{15}$

и)
$\frac{7}{37} + \frac{5}{51} = \frac{7*51}{1187} + \frac{5*37}{1187} = \frac{357+185}{1187} = \frac{542}{1187} \\ \\ \frac{7}{37} \ \textgreater \ \frac{5}{51}$

м) 
$\frac{9}{180} + \frac{7}{120} = \frac{1}{20} + \frac{7}{120} = \frac{6}{120} + \frac{7}{120} = \frac{13}{120} \\ \\ \frac{9}{180} \ \textless \ \frac{7}{120}$

Answer 2

2/9=16/72, 3/8=27/72.  2/9 < 3,8  ; 16/72+27/72=43/72
5/12=25/60, 4/15=16/60,  5/12 > 4/15;  25/60+16/60=41/60
7/37=357/1887,  5/51=185/1887  7/37 > 5/51;  357/1887+185/1887=542/1887
9/180=18/360,  7/120=21/360,  9/180 < 7/120;  18/360+21/360=39/360=13/120