What is the sum of the first five terms of the geometric series 3 − 6 + 12 − . . ?

3,−6,12,−24,...

You can rewrite this as:

(−1)n3⋅(1,2,4,8,...)

If we focus on 1,2,4,8...

an+1=2an
with a0=1.

This can be written out as a nice sum:
N∑n=02n=20+21+22+23+...
=1+2+4+8+...

Thus, now we can recombine everything to get:

3N∑n=0(−1)n2n

oof cheaters cheat because they’re lazy that’s why i cheat xd

: )

step-by-step explanation:

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk