Plotting this on graph paper first will definitely help if you are a visual person so, step 1:
Plot the coordinates given on an xy plane (you can draw a connecting line and extend it with an open ray
2. from the top point Q count over how many lines it is until you are above the midpoint M (this will give you the number needed to increase or decrease the x value by - since you are moving right it would be an increase if moving left it would be a decrease)
you should have moved right 10 units
3. from the top point Q count down how many lines until you are line up exactly with the midpoint M (this will give you the number needed to increase or decrease the y value by - since you are moving down it would be a decrease)
you should have moved down 14 units
4. from the midpoint M having coordinates (x,y) perform the following transformation (x,y) --> (x +10,y - 14) this is because of change rates determined in steps 2 & 3
5. This is how step 5 looks (x,y) for the mid point is (7,-9) so then the transformation would be (7 + 10, -9 -14)
6. Therefore the final result (the coordinates of the second endpoint R) would be (17, -23)
Hope that step by step helped!
