Answer:
Examination of the equation shows (graph):
x = 0, y = .5
Then .5 = c gives us the value of c giving
y = m x + .5 is our equation
Using y = 0, x = -1 gives
o = -1 * m + .5
m = .5
y = .5 x + .5 for the final equation
Check:
At x = 5, y = 3
3 = .5 (5) + .5 = 3
