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

This is the linear function ( the slope-intercept form ):
y = m x + b
If a line crosses the y-axis at ( 0, - 3 ) :  b = - 3
m = 3  ( a slope )
Answer:
y = 3 x - 3

Answer 2

Y=ax+b.
a=slope.
b=y-axis.
y=3x-3