tarea??

1.- a1= -27 d= 2 12 terminos


-27,-25,-23,-21,-19,-17,-15,-13,-11,-9,-7,-5

2.- a1= -34/9 d= 2/3 9 terminos

       1294704
=     _________
        177147

3.- a1= 67 d= -3.75 10 terminos
70.75, 74.5, 78.25, 82 ,85.75, 89.5, 93.25, 97, 100.75, 104.5


4.- a1= 128.15 d=-12.35 7 terminos
128.15,  11.58, 103.45, 91.1, 78.75, 66.4, 54.05


5.- a1= 63/7 d= -9/7 11 terminos

=   162
   _______
       7

6.- a1= -3 an= 187 n= -75
(-3+187)-75          (190)(-75)            14250
_________  =      __________  =     _______  =  7125
    2                             2                        2

7.- a1= 2 an= 215 n= 164

(2+215)164        (217)(164)           35588
__________  =  _________  =  _________ =17794
       2                      2                        2

8.- a1= 21 an= 276 n= 321

(21+276)              (297)(321)     95337
_________  =  _________ = ________   = 47668.5
   2                        2                      2
  
9.- a1= -78 d= -49

=-78+-49  (n-1)
=127(n-1)
n-1=127
n=127+1
n=128

10.- a1= 345 d= -169

=345+-169 (n-1)
=176(n-1)
n-1=176
n=176+1
n=128