Answer:
8184 vocalists sang in total
Step-by-step explanation:
The number needed is ...
8 + 16 + 32 + 64 + 128 + 256 + 512 + 1024 + 2048 + 4096
You can add these up to get a total of 8184, or you can use the formula for the sum of a geometric series:
Sn = a1(r^n -1)/(r -1) . . . . where a1 is the first term and r is the common ratio
S10 = 8(2^10 -1)/(2 -1) = 8(1024 -1)/1 = 8184
If the perimeter is known / given and is 6x, you can find the length of the unknown side by adding up the lengths of the other two sides and subtracting this sum from 6x:
6x - (x+3 + 2x + 4) = 6x - x - 3 - 2x - 4
Combining like terms, 3x - 7 represents the length of the unknown 3rd side.<span />
The formula for calculating length is:

We can also write

or

Why it does not matter?
Let's assume we have 2 numbers, a and b.
When we perform a subtraction:

, we get another number

When we perform another subtraction:

, we get a number

When we raise

or

to the power of 2, the result is the same,

.