Answer:
with what know question was there
Step-by-step explanation:
the formula for the sum of the first n terms of a geometric sequence is
Sn = s1(1 - r^n)/(1 - r)
with r being the common ratio and s1 is the first term.
so,
S15 = 7×(1 - (-3)¹⁵)/(1 - -3) = 7×(1 - -14,348,907)/4 =
= 7×14,348,908/4 = 7×3,587,227 = 25,110,589
Not sure
te rate is r
for decay, it is
A=P(1-r)^t
r=rate
P=present amount
dunno what b is
but I guess
A=28000(1-0.13)^t
A=28000(0.87)^t
I would guess the decay factor would be 0.87
In accordance with Pythagoras theorem ,
7^2 + 13^2 = x^2
49 + 169 = x^2
218 = x^2
√(218) = x
14.764 = x
.
Could u please manage with the triplet ..
.
Sorry abt that