Answer:
square numbers are numbers raised up to the power of two in essence the number multiplied by it self
-0.5,-0.4,-0.3,-0.1,0,1,2,3,4,4.17
(2+2i)(5+3i)
10+6i+10i+6i^2
10+16i+6(-1)
4+16i
When you have an “i^2”, you also have a negative one. The simplified answer is 4+16i
an = a1r^(n-1)
a5 = a1 r^(5-1)
-6 =a1 r^4
a2 = a1 r^(2-1)
-48 = a1 r
divide
-6 =a1 r^4
---------------- yields 1/8 = r^3 take the cube root or each side
-48 = a1 r 1/2 = r
an = a1r^(n-1)
an = a1 (1/2)^ (n-1)
-48 = a1 (1/2) ^1
divide by 1/2
-96 = a1
an = -96 (1/2)^ (n-1)
the sum
Sn = a1[(r^n - 1/(r - 1)]
S18 = -96 [( (1/2) ^17 -1/ (1/2 -1)]
=-96 [ (1/2) ^ 17 -1 /-1/2]
= 192 * [-131071/131072]
approximately -192