Ինքնուրույն աշխատանք 2

1. a1=10
   d=3                                                     
   n=7 
   an=?

An=a1+(n-1)d=28

     2)  a6+a8=13                                      

           a7=?   

a7=13/2=6.5

       3) a1=14                                                 

           a7=26                                                       

           S7=?    

S7=140

d=2 a2=16 a3=18 a4=20 a5=22 a6=24 a7=26

14+16+18+20+22+24+26=140

4) 8a6-5a9=12

a1=?

5) a3= -2                                  

a4= -3                                        

q=? 

q=-3/(-2)=1.5

6)a5-a1=9                            

a1+a3=3                                     

q=? a1=?  

a1=-0.5

7)1,1/2,1/4,……..                  

S=?  

8)a2=243                            

a5=9                                      

S5=?