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
63/84 divided by 21/21
=3/4
or
63 divided by 84=0.75 which is the same thing as 3/4
To rotate a figure
90 degrees(-y,x)
180 degrees(-x,-y)
270 degrees(y,-x)
If your original point is (1,2) or example and you want to rotate it say 270 degrees the final point would be (2,-1)
Hope this helped!!!!!
I believe it would be x=2i
:)