Step-by-step explanation:
M is the midpoint of AB. First, find the coordinates of M.
M = ((4 + 0) / 2, (2 + 4) / 2)
M = (2, 3)
Now find the slope of MC:
m = (15 − 3) / (8 − 2)
m = 12 / 6
m = 2
Find the slope of AB:
m = (4 − 2) / (0 − 4)
m = 2 / -4
m = -1/2
The slopes are opposite inverses, so the two are indeed perpendicular.
(1,5)&(8,5)
slope =(8-1)÷(5-5)
= 7÷0
the solution is undefined because any number which is divided by 0 is undefined
There are 4! = 24 poosible permutations of the four letters. Let the letters be A, B, C and D. Two permutations will have only letter A in the correct envelope, two more permutations will have only letter B in the correct envelope, two more will have only letter C in the correct envelope and two more will have only letter D in the correct envelope. Therefore 8 out of the 24 possible permutations will have only one letter with the correct address. The required probability is 8/24 = 1/3.