lets remember how to find the equation of a parallel line
two lines are parallel if they don"t intersect, that means they slopes are the same
y=-2x+3
slope as we see is m=-2
the other line has to pass through point (5,4)
y-y1=m(x-x1)
y-4=-2(x-5)
we solve the equation
y= 4-2x+10
y= -2x+14
i will send you a picture
green line is y=-2x+14