8 and 5 multiply to 40 but subtract to 3.
Formula of the sum of the 1st nth term in a Geometric Progression:
Sum = a₁(1-rⁿ)/(1-r), where a₁ = 1st term, r = common ratio and n= rank nth of term (r≠1)
Sum = (-11)[1-(-5⁸)] /[(1-(-5)]
Sum = (-11)(1- 390625)/(6)
SUM = 716,144
8
d
8
d
out of
32
d
4
+
8
d
32
d
4
+
8
d
.
8
d
(
4
d
3
+
1
)
