An airplane takes off with a full tank of 40,000 gallons of fuel and flies at an average speed of 550 miles per hour. after 8 hours in flight, there are 14,000 gallons of fuel left. it will take another 3.5 hours for the plane to reach its destination. how much fuel will be left in the tank when the plane lands? what is the total distance of the flight?

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.