Here, Add both the equations in order to eliminate y,
5x = 10
x = 10/5
x = 2
Now, substitute it in 1st equation,
8(2) - 4y = -32
-4y= -32- 16
y = -48/-4
y = 12
In short, Your Answer would be (2, 12)
Hope this helps!
1/2 is the probability the coin would land heads up both times.