The sum of a geometric sequence is:

s(n)=a(1-r^n)/(1-r) in our case:

s(n)=3(1-4^n)/(1-4)

s(n)=-(1-4^n)

s(n)=(4^n)-1 and s=1023

(4^n)-1=1023

4^n=1024

n ln4=ln1024

n=(ln1024)/(ln4)

n=5

4 0

3 years ago

Will give brainliest, pls help ASAP!

bekas [8.4K]

Step-by-step explanation:

2 × 10⁸ - 7 × 10⁷

= 200,000,000 - 70,000,000

=130,000,000

= 1.3 × 10⁸

6 0

2 years ago

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It says: Find the surface area of the rectangular prism with l=16 m, w=19 m, annd h = 2 m

ratelena [41]

The surface area of a rectangular prism needs an formula.
For a rectangular prism you have to understand some about the shape.
It is a 3D shape consisting of 6 sides
all are rectangles
to determine the area of one rectangle is the base multiplied by the height or in this case length times with.
but you also need to account for all sides and the height.
so the Surface area formula would be like
$sa = l \times w + l \times h + w \times h$
this accounts for 3 of the sides of the rectangular prism.
the top,bottom,and side.
so to get the surface area of a rectangle prism you must mutiply each side by 2 to account for all sides of the rectangular prism.
so the surface area formula for a rectangular prism is
$SA = 2\\ \times l \times w +2 \times l \times h+2 \times h \times w$
I won't solve it for you but just plug in your values for l,w,and h into that formula and you will get your answer in metres squared or m
${m}^{2}$

8 0

3 years ago

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G * 9 = 3.6 solve for G what is it​

G * 9 = 3.6 solve for G what is it