Question

Insira quatro meios aritméticos entre 5 e -20

Answer 1

an = a1 + (n-1) * r
-20 = 5 + (6-1) * r
-20 = 5 + 5r
5r = -20-5
5r = -25
r = -25/5
r = -5

P.A. (5,0,-5,-10,-15,-20)