If the three vertices A, B, and C in the three adjacent squares shown are collinear, find the value of x.
If A, B, and C are collinear, then the slope of BC = slope of AB,
i.e., 3/4 = y/7 → y = 21/4 = 5¼
x = 7 + y = 7 + 5¼ = 12¼.
Collinear Vertices of Squares
12.5