Hello from MrBillDoesMath!
Answer:
a^6 + 4 a^5 + 5 a^4 - 5 a^2 - 4 a - 1
Discussion:
You may need to clean things up a bit but suppose that
S(1) = a-1
S(2) = a^2 -1
Since this is a geometric series, the geometric ratio is given by
S(2)/ S(1) = (a^2 -1)/ (a-1)
= (a+1)(a-1)/ (a-1)
= a+1
Conclusion:
S(2) = (a+1) S(1) = (a+1) (a-1)
S(3) = (a+1) S(2) = (a+1) (a+1) (a-1) = (a+1)^ (3-1) (a-1)
S(4) = (a+1) S(3) = (a+1) * (a+1)^2 (a-1) ) = (a+1)^(4-1) (a-1)
in general.....
S(n) = (a+1)^ (n-1) (a-1)
So
S(6) = (a+1)^ (6-1) (a-1)
= (a-1) (a+1) ^ 5
= a^6 + 4 a^5 + 5 a^4 - 5 a^2 - 4 a - 1
Hope I didn't screw something here!
Thank you,
MrB
The answer to that would be 3/8
184/525
(this is me adding characters)
-24a²- 6a +9 = - 3(8a² +6a - 9)
8a² +6a - 9 =0
x=(-b +/-√(b² - 4ac))/2a
x = (-6 +/-√(36+4*8*9) /(2*8) = (-6 +/-√(324) /16 = (-6 +/-18)/16
x1 = (-6 +18)/16 = 0.75
x2 = (-6 -18)/16 = - 1.5
-24a²- 6a +9 = - 3(8a² +6a - 9) = -3(a - 0.75)(a + 1.5)
