Question

Determinati numarul natural n din egalitatea:

a) 5¹¹+¹²+¹³+...+30 = (5ⁿ)³•25

Answer 1

11+12+13+....30=41*20/2=410 5 la 410=5 la 3*n*5 la puterea2 5 la 410=5 la puterea (3n+2)=> 410=3n+2=> 3n=408=> n=136