1. For each pair of points, find a linear equation whose graph will go
through the two points. Use x to represent the first coordinate and
y to represent the second coordinate.
a. (4,9) and (6, 13)
b. (5, 13) and (3,7)
c. (8,8) and (20, 14)
d. (-2,5) and (1, -4)
