On a coordinate plane, vector v has a magnitude of 6 miles per hour in a northwesterly direction. What are the magnitude and direction of 2(−v)? A 12 miles per hour in a northwesterly direction B 8 miles per hour in a southeasterly direction C 12 miles per hour in a southeasterly direction D 8 miles per hour in a northwesterly direction

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  C 12 miles per hour in a southeasterly direction

Step-by-step explanation:

-v has a direction opposite to that of v. The opposite of northwest is southeast.

2(-v) means the magnitude of the opposite vector is multiplied by 2. 2 times 6 mph is 12 mph.

  2(-v) is 12 mph in a southeasterly direction

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'.