Question

Numerele rationale a b c sunt direct proportionale cu 0.(2) 0.(3) 0.(4).Stiind ca c-a=10 determinati valorea sumei a+2b+c

Answer 1

Explicație pas cu pas:

0,(2)=2/9

0,(3)=3/9=1/3

0,(4)=4/9

a/(2/9)=b/(1/3)=c/(4/9)=k

a=2k/9

b=k/3

c=4k/9

4k/9-2k/9=10

2k/9=10

2k=90

k=45

a=10

b=15

c=20

10+2•15+20=10+30+10=50

a+2b+c=50