$\bf \qquad \qquad \textit{sum of a finite geometric sequence} \\\\ S_n=\sum\limits_{i=1}^{n}\ a_1\cdot r^{i-1}\implies S_n=a_1\left( \cfrac{1-r^n}{1-r} \right)\quad \begin{cases} n=n^{th}\ term\\ a_1=\textit{first term's value}\\ r=\textit{common ratio}\\ ----------\\ a_1=2\\ r=8\\ n=4 \end{cases} \\\\\\ S_4=2\left( \cfrac{1-8^4}{1-8} \right)\implies S_4=2\left( \cfrac{-4095}{-7} \right) \\\\\\ S_4=2(585)\implies S_4=1170$

6 0

2 years ago

Stephen is using a map to plan a hike. The map is based on a scale of 1:40,000, in cm. If the route is 10 cm on the map, how man

kvasek [131]

1/40,000 = h/10
40,000h = 10
h = 10/40,000
h = 1/4,000

5 0

2 years ago

Please help with the following question

Mrrafil [7]

The generic equation of the line is:
y-yo = m (x-xo)
The slope is:
m = (y2-y1) / (x2-x1)
m = (- 2-0) / (3-0)
m = -2 / 3
We choose an ordered pair
(xo, yo) = (0, 0)
Substituting values:
y-0 = (- 2/3) (x-0)
Rewriting:
y = (- 2/3) x
Answer:
The equation of the line is:
y = (- 2/3) x

4 0

3 years ago