Answer:
Correct choice is B
Step-by-step explanation:
Let a, b, c and d be the trapezoid's sides lengths.
The perimeter of the trapezoid is the sum of all sides lengths, thus,

If each side length is increased by a factor 7, then new sides have lengths 7a, 7b, 7c and 7d. The perimeter of new trapezoid is

Use the distributive property for this expression:

Since
then

Answer:
For k = 6 or k = -6, the equation will have exactly one solution.
Step-by-step explanation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots
such that
, given by the following formulas:



If
, the equation has only one solution.
In this problem, we have that:

So




We will only have one solution if
. So





For k = 6 or k = -6, the equation will have exactly one solution.
Answer:
5
Step-by-step explanation:
Answer:
mean = 77
Step-by-step explanation:
We have a confidence interval of (59, 95) with a confidence of 99.7 percent
99.7 is 6 standard deviations from the mean, 3 on each side of the mean
mean - 3 sigma = 59
mean + 3 sigma = 95
We can use elimination to eliminate sigma. Add these equations together
mean - 3 sigma = 59
mean + 3 sigma = 95
---------------------------------
2 * mean = 154
Divide each side by 2
2 * mean/2 = 154/2
mean = 77