We can use the points (0, -3) and (6, 0) to solve.
Slope-intercept form: y = mx + b (m = slope and b = y-intercept)
First, find the slope.
Slope formula: y2-y1/x2-x1
= 0-(-3)/6-0
= 3/6
= 1/2
Second, find the y-intercept.
y = mx + b
y = 1/2 + b
-3 = 1/2(0) + b
-3 = b
Third, put into final form.
y = 1/2x - 3
Best of Luck!