First write the equations given to you in the problem
V = 6D
V + D = 14
using substitution you need to find one of the variables
6D + D = 14
7D = 14
D = 2
Pick one equation to solve for the other variable
V = 6D
V = 6×2
V = 12
Then ALWAYS Check your answer with the other equation
12 + 2 = 14
Videl watched TV for 12 hours and Dineen watched TV for 2 hours.
The conclusion to draw from this is both people watch way too much TV and need to exercise more.
Hope this helped! If you need more help just comment on my answer! :)