<span>c. 4.6
21 X .22= 4.6
Calculating the variance requires finding the product of 21 and 22%. To make this easier we convert 22% into it's decimal form and construct the equation. To back check this answer we can use 10% of 21 voters which equals 2.1% then double that amount to reach 4.2%, knowing that we now have a close approximation of the variance we can eliminate answers a, b, and d, leaving c as the only logical choice.</span>
Answer:
33/4
Step-by-step explanation:
Let the first number be x, and the second number be y.
x - y = 4
x + y = -7
Solve for x in the first equation.
x - y = 4
x = 4 + y
Put x as (4 + y) in the second equation and solve for y.
4 + y + y = -7
4 + 2y = -7
2y = -7 - 4
2y = -11
y = -11/2
Put y as -11/2 in the first equation and solve for x.
x - y = 4
x - (-11/2) = 4
x + 11/2 = 4
x = 4 - 11/2
x = -3/2
Their product is:
-11/2 × -3/2
33/4
I believe that the answer is 20. I am not entirely sure though.
