Consider the following geometric sequence -5,10,-20,40,...If the reclusive formula for the sequence above is expressed in the form a^n = b*a^n-1 , determine the value of b

Hello from MrBillDoesMath! Answer:   b = -2 Discussion: Let's analyze this sequence.  The first number = -5                               a(0)The second number = 10 = -5 (-2)          a(1) = a(0) *-2the third number  = -20 = 10 * (-2)          a(2) = a(1) * -2The fourth number = -20 * (-2)                a(3) - a(2) * -2
In other words, the recursive (not reclusive) formula isa(0) = -5         (this need to be stated! Not stated in the problem)a(n) = a(n-1) * (-2)This implies that "b" = -2.
Regards, MrB