Question

calculati: A=3/2x5+4/5x+5/9x14+7/14x21
pls imi trebuie repede!

Answer 1

Salut,

vom tine cont de urmatoarea identitate : m/k(k+m) = 1/k-1/(k+m) (se demonstreaza foarte usor)

A=3/2*5+4/5*9+5/9*14+7/14*21

A=1/2-1/5+1/5-1/9+1/9-1/14+1/14-1/21 = 1/2- 1/21 = 19/42

Sper ca te-am ajutat!