ANSWER
y=-1
EXPLANATION
The given line in the graph has equation
[tex]y = 2.5[/tex]
This line is a horizontal line.
All horizontal line has a slope of 0.
Let the equation of the line that is parallel to this line be
[tex]y = mx + b[/tex]
The slope of this line must also be zero.
We substitute the slope, m=0 and the point (3,-1) into this equation to get:
[tex] - 1 = 0(3) + b[/tex]
[tex] \therefore \: b = 0[/tex]
Hence the required equation is
[tex]y = - 1[/tex]
