Answer:
R=2
Step-by-step explanation:
x = 4 is a vertical line parallel to the y-axis and passing
through all points in the plane with an x-coordinate of 4
x = 2 is parallel to x = 4 so is a vertical line
passing through all points with x-coordinate of 2
plot 2 or 3 points with an x-coordinate of 2 and draw a straight line through them
for example
( 2 , − 5 ) , (2 , 0 ) , ( 2 , 3 )
graph{(y-1000x+4000)(y-1000x+2000)=0 [-10, 10, -5, 5]}