Question

Maria si-a planificat rezolvarea temei in 4 saptamani. In prima saptamana a rezolvat 0,(3) din probleme. In a doua 0.(6) din rest, in a treia jumatate din noul rest iar ultima 10 probleme. Cate probleme a rezolvat la inceput?

Answer 1

Notezi cu x numarul de probleme
I. 0,(3)·x=3/9·x=1/3·x=x/3
Rest: x-x/3=3x/3-x/3=2x/3

II.0,(6)·2x/3=6/9·2x/3=4x/9
Rest: 2x/3-4x/9=6x/9-4x/9=2x/9

III.2x/9:2=2x/9·1/2=2x/18=x/9

IV.10

x/3+4x/9+x/9+10=x
3x/9+4x/9+x/9+90/9=9x/9 |·9
3x+4x+x+90=9x
8x+90=9x
9x-8x=90
x=90 de probleme a rezolvat in total

In prima saptamana a rezolvat x/3=90/3=30 de probleme