Question

15) calculati c) 11/20+7/10+5/16 d) 16/21+3/28+1/42​

Answer 1

Răspuns:

Explicație:

11/20 + 7/10 + 5/16 =  

20=2²·5

10=2·5

16=2⁴

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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

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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