Dina leaves her house driving east at 35 miles per hour. Thirty minute later, her husband John notices she forgot her cell phone and sets off after her. How fast must John travel in order to catch up with Dina 2 hours after he leaves?

John must travel at 43.75 mph

Step-by-step explanation:

Let x represent how fast John should travel in order to catch up with Dina 2 hours after he leaves.

By the time they meet, they would have covered the same distance.

Distance = speed × time

Dina leaves her house driving east at 35 miles per hour. Distance covered by Dina in 2 hrs 30 minutes is

35 × 2.5 = 87.5 miles

Thirty minute later, her husband John notices she forgot her cell phone and sets off after her.

Distance travelled by John in 2 hours is x × 2 = 2x

Since they covered the same distance, then

2x = 87.5

x = 87.5/2 = 43.75

30

step-by-step explanation:

times by times

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'.