Răspuns:
Explicație pas cu pas:
a) (1/2+3/4+5/6)+(1/2+1/4+1/6)=(1·6+3·3+5·2)/12+(1·6+1·3+1·2)/12=
(6+9+10)/12+(6+3+2)/12=25/12+11/12=(25+11)/12=36/12=3·12/12=3
b (3/2+7/5+5/9)+(3/2+8/5+22/9)=
(3·45+7·18+5·10)/90+(3·45+8·18+22·10)/90=
(135+126+50)/90+(135+144+220)/90=311/90+499/90=810/90=9·90/90=9
