There is a line whose y-intercept is 9 and whose slope is 0. The point (1, –9) What is its equation in slope Y-intercept form?

Question

What is the equation of y=?

Answer 1

it's a flat horizontal line with slope = 0, so y never changes

y=9 is the equation

you probably mean (1,9) not (1,-9) as the point on the line

Answer 2

Your first sentence makes this is a horizontal line whose equation is y = 9.

Your second and third sentences are inconsistent with the first .Perhaps you made a typo.