Question

What is the equation of a horizontal line that has a y-intercept of 3.5?

Answer 1

First, recall that the equation of a line is

y = mx+b

where 

m = slope
b = y-int

The key to this question is the details :

Horizontal line ---> This tells you that your slope is 0

y-int = 3.5 -----> In the equation above, b=3.5

Therefore,

y = 0x + 3.5
y = 0 + 3.5
y = 3.5