In B 5^2 = 25. There is no x anywhere.
In C f(x) = 2/x is a function of a reciprocal, not a quadratic.
In D f(x) = 2x^3 + 3x^2 - 5 is a cubic. A cubic is not a quadratic. The highest power of a quadratic is x^2
That leaves A. When you expand the brackets, you get
3(x^2 + 3x- 4x - 12)
2(x^2 - x - 12) when you remove the brackets you get
2x^2 - 2x - 24. The highest power of x is x^2. This is your quadratic.
A<<<< answer.
Answer:
The standard deviation of the sample mean differences is _5.23_
Step-by-step explanation:
We have a sample of a population A and a sample of a population B.
For the sample of population A, the standard deviation
is

The sample size
is:
.
For the sample of population B, the standard deviation
is

The sample size
is:
.
Then the standard deviation for the difference of means has the following form:

Finally

Answer:
1 1/3
Step-by-step explanation:
1/3 divided by 1/4
keep change flip so 1/3 times 4/1 multiply straight across
I'm guessing these are regular polygons so... here goes.... 11. angle 1 is (8-2)*180= 1080 then divide that by 8 (how many angles there are ) to get 135. angle 2 is 360/8 (the sum of the exterior angle is always 360) which is 45 and multiply it by 2 (because the two polygons are stuck together) to get 90.
12. it says 2 squares so angle 4 is definitely 90. angles 3 and 5 would be 45 because it's an isosceles right triangle meaning that 1 angle is 90 and that the total of the other two angles would be 90 as a triangle angle sum is 180 and since it's isosceles just divide 90 by 2 because the 2 angles are the same getting 45for angles 3 and 5.
13. the triangle includes 2 exterior angles so...360 divided by 8 = 45 (this is the measure of each exterior angle of the polygon)
45 x 2 cause as I said it includes 2 exterior angles to get 90. it's a triangle so 180 (the sum of angles in triangle) minus 90 to get 90. so 1 and 2 are both 45 and 3 is 90