Answer:
Explanation:
Equation of a straight line is given as
y=mx+c
So we are given equation
y=6
This shows that m=0
Then the graph is a straight horizontal line cutting y at 6
The only slope that will be parallel to this is
y=mx+c, then m=0
y=c is the only line parallel to y=6
So, c can take on any finite values and it will be parallel to line y=6
So the slope of the line that will be parallel to y=6 is zero i.e m=0