If the points are collinear, then that means they lie on the same line when connected to each other. In order to prove this, the distances between the points must sum up to the length of the line.
AB + BC = AC
7 + 4 ? 9
11 ≠ 9
Since they do not sum up, therefore, the points are not collinear.
x -y = 1
5x + 3y = 45
Solve the first equation for x: x = y + 1
Substitute x in the second with y + 1
5x + 3y = 45
5(y + 1) + 3y = 45
5y + 5 + 3y = 45
8y + 5 = 45
8y = 40
y = 5
Substitute 5 for y in x = y + 1
x = y + 1
x = 5 + 1
x = 6
Answer: (6, 5)
