Question

Se dau fractiile ordinare ireductibile:
6/125
7/12
1/4
1/250
2/15
13/40
5/30
11/200
3/8
9/50
29/2
10/3
3/5
103.400
a) Scrieti-le pe acelea care se transforma in fractii zecimale finite
b) Amplificandu-le corespunzator,transformati fractiile gasite la punctul a) in fractii zecimale

Answer 1

se transforma in fractiizecimale finite acele fractiial caror numitor, descompus in factori primi  are  numai puteri ale lui 2 si/sau 5

deci finite sunt
6/125=6/5³
1/4=1/2²
1/250=1/2*5³
13/40=...vezi tu
11/200=..idem
3/8
9/50
29/2
3/5
103/400




6/125=6*8/125*8=48/1000=0,048 (potiverifica pe calculator)
1/4=1*25/4*25=25/100=0,25
1/250=4/1000=0,004
13/40=13*25/40*25=325/1000=0,325

11/200=55/1000=0,055

3/8=3*125/8*125=375/1000=0,375
9/50=18/100=0,18

29/2=29*5/2*5=145/10=14,5

3/5=6/10=0,6

103/400=103*25/400*25=2575/10000=0,2575