The sum if the geometric sequence given by:
an=-2(3)^(n-1)
will be:
when:
n=1
an=-2
when n=2
a2=-6
when n=3
a3=-18
when n=4
a4=-54
when n=5
a5=-162
when n=6
a6=-486
when n=7
a7=-1458
when n=8
a8=-4374
thus the summation of the term will be:
Sn=(-4374+-1458+-486+-162+-54+-18+-6+-2)
Sn=-6560
the answer is -6560
Answer:
25. a = 60
26. a = 17
Step-by-step explanation:
In these two problems we are going to use a property of parallelograms that says: opposite angles have equal measure
so we have
25.

and for 26 we have

Well, after doing all that math, here is what I came up with, I hope this helps! :) -1600x^2+28265x-21830