Erica watched 1 4 of a movie in the morning, and she watched some more at night. By the end of the day, she still had 2 3 of the movie left to watch. How much of the movie did Erica watch at night?

1/6 of the movie

Step-by-step explanation:

You have already done half of it. Now substitute for x1 = 4 and y = 5
y - 5 = 6/7(x - 4)
Multiply everything by 7 to remove fractions
7y - 35 = 6(x - 4)
7y - 35 = 6x - 24
-6x + 7y = -24 + 35
-6x + 7y = 11

Some people prefer a positive number in front of x so multiply by -1
6x - 7y = -11

You can check the answer by testing it works for both of the original points
6x4 - 7x5 = 24 - 35 = -11 true
6x-3 - 7x-1 = -18 - -7 = -11 true