Question

Suma a cinci numere nat. impare consecutive este egala cu 105.Aflati numerele.

Answer 1

Notam numerele
(2a+1),(2a+3).(2a+5),(2a+7),(2a+9)
2a+1+2a+3+2a+5+2a+7+2a+9=10a+25
10a+25=105
10a=105-25
10a=80
a=80/10
a=8
de aici rezulta ca numerele sunt:
2a+1=2*8+1=17
2a+3=2*8+3=19
2a+5=2*8+5=21
2a+7=2*8+7=23
2a+9=2*8+9=25

Answer 2

Notam cu a numarul natural .

$2a+1+2a+3+2a+5+2a+7+2a+9 = 105 \\ 10a + 25 = 105 ==> 10a = 80 \\ a=8$

In concluzie numerele cautate sunt : 17,19,21,23,25 !