Question

Calculați:2,25(3) b)5,4-4,1(6) c) 5(5)+4,(4) d)0,8(3)-0,(21)​

Answer 1

Răspuns:

Calculați:

a)2,25(3) =2si(253-25)/900=2 228/900

(1800+228/900=2028/900=57/225=19/75

b)5,4-4,1(6)=5,4-25/6=54/10-25/6=

27/5-25/6=37/30

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

50/9+40/9=90/9=10

d)0,8(3)-0,(21)=(83-8)/90-21/99=

75/90-7/33=¹¹5/6-²7/33=(55-14)=41/66

Answer 2

Răspuns:

a) $2,25(3) = \frac{2028}{900}$

b) 5,4 - 4,1(6) = 49,8(3)

c) 5,(5) + 4,(4) = 10

d) 0,8(3) - 0,(21) = 0,6(21)

Explicație pas cu pas:

a)

$2,25(3) = \frac{2253-225}{900} = \frac{2028}{900}$

b)

$5,4 - 4,1(6) = \frac{54}{10} - \frac{416-41}{90} = \frac{54}{10} - \frac{375}{90} = \frac{54*9-375}{90} = \frac{4860 - 375}{90} = \frac{4485}{90} = 49,8(3)$

c)

$5,(5)+4,(4) = \frac{55-5}{9} + \frac{44-4}{9} = \frac{50+40}{9} = \frac{90}{9} = 10$

d)

$0,8(3) - 0,(21) = \frac{83-8}{90} - \frac{21}{99} = \frac{75}{90} - \frac{21}{99} = \frac{5}{6} - \frac{7}{33} = \frac{5*11 - 7*2}{66} = \frac{55-14}{66} = \frac{41}{66} = 0,6(21)$