Question

Qual é a soma ,
Calcule a soma dos 50° termo da PA (3, 7, 11) ?

Answer 1

a1= 3

r= 4

n = 50

a50 = 3+49.4 ==> 3+196 ==> 199

S50 = (3+199).50 ==> 202.25 ==> 5050

               2

Answer 2

A1 = 3

R = 4

N = 50

An = X = 199

An=A1+(N-1).R

x=3+(50-1).4

x=3+49.4

x=3+196

x=199

S50 = (3+199).50

                2

S50 = 202.25

S50 = 5050