Question

Consider the following geometric sequence

-5,10,-20,40
if the explicit formula for the sequence above is expressed in the form an=b*c^n-1, determine the values pf b and c

b=
c=

Answer 1

hello :
an=b*c^n-1, b ; the first term c : common ratio
b=-5 c=40/-20=-20/10 = 10/-5 = -2