Răspuns:
Explicație pas cu pas:
S = suma initiala
Prima data 2S/9 + 7
Rest S - (2S/9 + 7) = S - 2S/9 - 7 = 7S/9 - 7
A doua oara 3/7 *(7S/9 - 7) + 4 = 3S/9 - 1 + 4 = 3S/9 + 3
Rest 7S/9 - 7 - 3S/9 - 3 = 4S/9 - 10 = 3,92
4S/9 = 13.92
S = 13,92*9/4 = 31,32 RON