Which equation represents a line that is perpendicular to the line represented by 2x - y = 7 ?

1) y = -1/2x + 6
2) y= 1/2x + 6
3) -2x + 6
4) y = 2x + 6

Hello:
the equation is : y = ax+b
the slope is a : a×(2) = -1( perpendicular to a line with a slope of   2)            because :     2x-y =7     ..y=2x-7   )     

a = -1/2        y=(-1/2)x+b ( exemple :  1) y = -1/2x + 6 )

step-by-step explanation:

if x = 2 you have to find x to finish the problem