y= 1/2x + 4
is often how people write
y= (1/2)x + 4
a parallel line has the same slope = the coefficient of the x term, when the linear equation is solved for y.
a parallel line would be y= (1/2)x + b where b is any real number except 4. If b=4, it would no longer be a parallel line, but it would be the same identical line
so, a parallel line would be
y = x/2 +2
y= x/2 +3
y= x/2 +5
y= x/2 -4
but as written it says y = 1/2x + 4 which is a rectangular hyperbola, not a linear equation.
still same result for a parallel line, just change 4 to any real number and the curved line is parallel to the original line