Question

Gigel cheltuie o suma de bani astfel:prima data 2 supra noua din suma initiala plus 7 lei,a doua oara 3 supra 7 din rest plus 4 lei,ramanandu-i 3,92
lei.care a fost suma initiala?

Answer 1

x=suma initial
2x/9+7= cheltuiala 1
x-2x/9-7=7x/9-7=rest
(7x/9 -7)* 3/7 +4=x/3-3+4x/3+1 =cheltuiala 2
2x/9+7+x/3+1+3,92=x
2x/9+x/3+11,92=x
2x+3x+134,28=9x
4x=107,28
x=26,82 lei

cheltuiala 1= 26,82 * 2/9 +7=5,96+7=12,96 lei
                   26,82-12,96=13,86 lei
cheltuiala 2= 13,86 * 3/7 +4=5,94+4=9,94 lei
rest                 13,86-9,94=3,92