Question

5.Scrieți sub formă de fracție ordinare ireductibile următoarele fracții zecimale periodice simple. Ajutor ex 5 ;6;7​

Answer 1

5.

a)

$\frac{33-3}{9} =\frac{30}{9}=\frac{10}{3}$

b)

$\frac{5}{9}$

c)

$\frac{18}{99}=\frac{2}{11}$

d)

$\frac{209-2}{99}=\frac{207}{99}=\frac{23}{11}$

e)

$\frac{1074-1}{999}=\frac{1073}{999}$

f)

$\frac{476190}{999999} =\frac{52910}{111111}$

6.

a)

$\frac{183-18}{90}= \frac{165}{90} =\frac{55}{30} =\frac{11}{6}$

b)

$\frac{216-21}{90} =\frac{195}{90}=\frac{13}{6}$

c)

$\frac{61-6}{90}=\frac{55}{90}=\frac{11}{18}$

d)

$\frac{2083-208}{900} =\frac{1875}{900} =\frac{125}{60}=\frac{25}{12}$

f)

$\frac{1136-11}{9900} =\frac{1125}{9900} =\frac{75}{660} =\frac{15}{132} =\frac{5}{44}$

7.

a) 2,25+3,(3)=5,58(3)

b) 5,4-4,1(6)=1,2(3)

$\frac{54}{10} -\frac{416-41}{90}$

$\frac{54}{10}-\frac{375}{90}=\frac{486-375}{90} =\frac{111}{90}=\frac{37}{30} =1,2(3)$

c) 5,(5)+4,(4)=9,(9)

d) 0,8(3)-0,(21)=0,62(12)

$\frac{83-8}{90}-\frac{21}{99} =\frac{75}{90}-\frac{7}{33} =\frac{15}{18} -\frac{7}{33}= \frac{495-126}{594} =\frac{369}{594}=\frac{41}{66}=0,62(12)$