Answer:
y = - 3
Explanation:
a line with a slope of zero is a horizontal line, parallel to the x- axis with equation
y = c ( where c is the value of the y- coordinates the line passes through )
the line passes through (0, - 3 ) , the y- intercept with c = - 3 , then
y = - 3 ← equation of line
note this equation cannot be expressed in slope- intercept form