Answer:
Step-by-step explanation:
The answer is b
A.
In the first generation we have 2 ancestors.
In the second generation we have 4 ancestors or

ancestors.
In the third generation we have 8 ancestors ot

ancestors.
We can see that each succesive generation has two times more members. The sum is:

To calculate number of ancestors we can use formula <span>for the sum of a geometric sequence. Geometric sequence is sequence of numbers that differ by a certain factor. This factor is called ratio. Formula is:
</span>

<span>Where:
S -> sum
a1 -> first member of a sequence
r -> ratio
n -> number of elements
For this question:
a1 = 2
r = 2
n = 40
</span>

<span>
b.
1 generation = 25 years
40 generations = 40 * 25 = 1000 years
c.
Total number of people who have ever lived = </span>

Number of ancestors in 40 generations =

The number of ancestors is greater than total number of people who have ever lived. This means that not all ancestors were distinct and that in each generation both men and women had children with more than one partner.
Answer:
320???
Step-by-step explanation:
You already have it answered
Answer:
C. the subtraction property of equality
Step-by-step explanation:
12-x = 7x + 32
Step - 1: -x = 7x + 20
In that case, we just swap 12 from the left side to right side, and then we subtract 12 from 32 which is on the right side. Therefore, we do not multiply, divide or add anything. So, the option "C" is correct.
Step 2: -8x = 20
In that case, we again subtract 12 by interchanging the side. Moreover, we change the side of 7x to deduct it from -x.
Therefore, in both the cases, we use the subtract property of equality.