formula: y = mx + b
current points we know:
m = 1/2
x = 10
y = 0
so we solve for the b value.
0 = 1/2 (10) + b
0 = 5 + b
(inverse operation we subtracted 5 on both sides)
-5 = b
so the equation for a line with slope 1/2 passing through the point (10,0) is
y = (1/2)x + (-5) or y = (1/2)x - 5
(not sure if this is correct...)