Question

If a line crosses the y-axis at (0, -3) and has a slope of 3, what is the equation of the line?

Answer 1

General equation of the line is 
y = mx + b
m = 3
so y=3x+b

now find b
-3=3(0)+b
-3=b

so the equation is
y = 3x - 3

Answer 2

General equation of the line is 
y = mx + c

c = -3
m = 3

so the equation is
y = 3x - 3