Question

Cum se rezolva fractiile 11/20+7/10+5/16
16/21+3/28+1/42
18/15+11/18+4/45

Answer 1

11/20 + 7/10 + 5/16 = 
20=2²·5
10=2·5
16=2⁴
_______
c.m.m.m.c.=2⁴·5=80 - numitorul comun
(11·4+7·8+5·5)/80=(44+56+25)/80=125/80=25/16

16/21 + 3/28 + 1/42=
21=3·7
28=2²·7
42=2·3·7
_______
c.m.m.m.c.=2²·3·7=84 - numitorul comun
(16·4+3·3+1·2)/84=(64+9+2)/84=75/84=25/28

18/15 + 11/18 + 4/45 = 
15=3·5
18=2·3²
45=3²·5
_______
c.m.m.m.c.=2·3²·5=90 - numitorul comun
(18·6+11·5+4·2)/90=(108+55+8)/90=171/90=19/10

Answer 2

Sper că te-am ajutat.