Find the 12th term of the geometric sequence 10, -50, 250

Answer 1

10, -50, 250 as a geometric sequence has common ratio = r = -5

a1 =10

a2 =10(-5)

a3 =10(-5)^2

an=a1(r)^(n-1) = 10(-5)^(n-1)

a12 = 10(-5)^11 = -488,281,250 = about negative half billion