So in plain English it's saying if A Is an element of B, then A and B equals A or B. This is true sometimes
The answer is c hope this helps!!!
First of all calm down and brake down the problem plan a is $25 a month while the other one is $40 you need to subtract to get $15 than divide $15 by $0.25 which you will get 60 but this is not the right answer because its asking you how many phone calls is the cost of plan b less than the cost of plan a so the answer is 59 calls.
Answer:
1. √74; 2. (24.5, 21.5)
Step-by-step explanation:
1. Distance
You could use the distance formula to calculate the length of PQ, but I prefer a visual approach, because it requires less memorization.
Draw a horizontal line from P and a vertical line from Q until they intersect at R (28, 19).
Then you have a right triangle PQR, and you can use Pythagoras' theorem to calculate PQ.

2. Midpoint of line
The coordinates of the midpoint are half-way between the x- and y-coordinates of the end points.
For the x-coordinate, the half-way point is
(21 + 28)/2 = 49/2 = 24.5
For the y-coordinate, the half-way point is
(19 +24)/2 = 43/2 = 21.5
The coordinates of the midpoint M are (24.5, 21.5).