To use the elimination/addition method, you can think of each pair of like terms within the equations as being within a column. So, the -5x and 3x are in one column, the y and -8y are in a column, and the -3 and 24 are in a column.
The goal is to "eliminate" one of the unknown variables, in this case, x or y. To do that, we can multiply one or both of the equations by a number that will allow us to easily add the two equations together to eliminate a variable.
In this case, I think it would be easiest to multiply the top equation by 8, and receive the following:
-40x + 8y = -24
3x - 8y = 24
Now we can add these two equations together by adding up the columns (described above). This will eliminate the 8y and -8y to get the following:
-37x + 0 = 0
-37x = 0
Solve for x,
x = 0
Lastly, you can plug in this value for x into either of the initial equations to find y, but I will leave this for you to finish.
