Question

Determine o vigésimo termo da P.A (¼, 7/12...)

Answer 1

a1 = 1/4
a2 = 7/12
r = 7/12 - 1/4 = ( 7 - 3)/12 = 4/12 = 1/3 *****
n = 20
a20 = a1 + 19r
a20 = 1/4 + 19( 1/3)
a20 = 1/4 + 19/3 = ( 3 + 76)/12 = 79/12  ******