Answer:
y = - 1
Step-by-step explanation:
y = 4 is the equation of a horizontal line parallel to the x- axis.
A line parallel must therefore be a horizontal line with equation
y = c
where c is the value of the y- coordinates the line passes through.
The line passes through (2, - 1) with y- coordinate - 1, thus
y = - 1 ← equation of parallel line
