Question

Вычислить сумму 1/(1*2) + 1/(2*3) + 1/(3*4) + ...+1/(99*100)

Answer 1

(1/1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/99-1/100)=1/1-1/100=100-1/100=99/100