👤

Daca 1+3+5+7+.......+15=x
la puterea 3, atunci x este egal cu.....


Răspuns :

1+2+3+....+15-2-4-6-...-14=x³
15*16/2-2(1+2+3+...+7)=x³
15*8-2*7*8/2=x³
15*8-7*8=x³
8(15-7)=x³
8²=x³
(2³)²=x³
(2²)³=x³
4³=x³⇒x=4