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

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

Answer 2

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