The generic equation of the line is:
y-yo = m (x-xo)
Where,
m = (y2-y1) / (x2-x1)
Substituting values:
m = (20-15) / (10-5)
m = (5) / (5)
m = 1
We choose an ordered pair:
(xo, yo) = (5, 15)
Substituting values:
y-15 = 1 (x-5)
y = x - 5 + 15
y = x + 10
Answer:
An equation of the line that passes through the points (5 15) and (10 20) is:
y = x + 10