Răspuns :
a1=2 si a2=5 rezulta ca ratia r=a2-a1=5-2=3
S10=a1+a2+a3+a4+a5+a6+a7+a8+a9+a10=2+5+8+11+14+17+20+23+26+29==155
S10=a1+a2+a3+a4+a5+a6+a7+a8+a9+a10=2+5+8+11+14+17+20+23+26+29==155