Respuesta :

since it is a straight horizontal line, the slope is 0
TSO
y = mx + b

where m is the slope and b is the y-intercept.

y = 4

is what we are given.

That means that if the slope equals to 0 then:

y = 0x + 4

then

y= 4

So that means the slope for y=4 is 0.