Which of the following is the equation of a line perpendicular to y=12x+5y = \frac{1}{2}x + 5y=21x+5?
y=12x+3y = \frac{1}{2}x + 3y=21x+3
y=−2x+1y = -2x + 1y=−2x+1
y=2x−3y = 2x - 3y=2x−3
y=x+5y = x + 5y=x+5