Question

p.a a10=-2 e r=2÷3.Calcule a1

Answer 1

P.A.(
a 10 = -2
r = 2/3
a 1 = ?

a 10 = a 1 + (n - 1 ).r
a 10 = a 1 + (10 - 1 ).2/3
a 10 = a 1 + 9.2/3
a 10 = a 1 + 18/3
a 10 = a 1 + 6
a1 + 6 = a 10
a 1 = a 10 - 6
a 1 = -2 - 6
a 1 = -8