Let's start from what we know.

Note that:

(sign of last term will be + when n is even and - when n is odd).
Sum is finite so we can split it into two sums, first

with only positive trems (squares of even numbers) and second

with negative (squares of odd numbers). So:

And now the proof.
1) n is even.
In this case, both

and

have

terms. For example if n=8 then:

Generally, there will be:

Now, calculate our sum:



So in this case we prove, that:

2) n is odd.
Here,

has more terms than

. For example if n=7 then:

So there is

terms in

,

terms in

and:

Now, we can calculate our sum:




We consider all possible n so we prove that:
Answer:
1840
Step-by-step explanation:
345+23=368*5
The answer to your question is D
.5 x 8= 4 pounds
.5 x 10=5 pounds
.5 x 12=6 pounds
.5 x 16=8 pounds
Answer:
150 ft^3
.1 ton or 200 lbs
Step-by-step explanation:
The volume is given by
V = l*w*h
V = 5*5*6
V = 150 ft^3
To find how much 1 ft^3 weighed take the weight and divide by the volume
15 tons / 150 ft^3
.1 ton / 1 ft^3
1 ft^3 weights .1 ton
We know that 1 ton = 2000 pounds
.1 ton = 200 pounds
Okay so basically it's like 4 to the power of 5 and like that and the • means multiply