Răspuns:
Explicație pas cu pas:
X+4/5+x+5/6+x+6/7+......+x+99/100=96
In suma sunt 99-4 +1 termeni de forma x +a/b
96x +4/5+5/6+6/7+....+99/100=96
4/5 = 1-1/5, 5/6 = 1-1/6, ..., 99/100 = 1-1/100
96x +96 - (1/5+1/6+1/7+....+1/100) = 96
96x = (1/5+1/6+1/7+....+1/100)
x = (1/5+1/6+1/7+....+1/100)/96
Suma S = 1/5+1/6+1/7+....+1/100 poate fi calculata
doar cu calculatorul, nu exista o formula