Question

Determine a PG na qual a4=1/6 e a7=9/2

Answer 1

a1q³ = 1/6
a1q⁶ = 9/2

a1q⁶/a1q³  = (9/2) / ( 1/6)
q³ = 27
Nota: 9/2 : 1/6 = 9/2 * 6/1 = 27 ***
q³ = 3³
q = 3 ****
a1 * q³ =  1/6
a1 * 3³ = 1/6
27a1 = 1/6
a1 = 1/6 : 27/1 = 1/6 * 1/27 = 1/162 ***

PG
a1 = 1/162
a2 = 1/162 * 3 =  3/162 = 1/ 54
a3 = 1/54 * 3 =  3/54 = 1/18
a4 = 1/18 * 3 =  3/18 = 1/6