To solve this system of equations, we can use substitution or elimination method.

Let's solve by substitution method:

From the first equation, we can express y in terms of x:
y = -1 - 3x

Substitute this expression for y into the second equation:
x - x(-1 - 3x) = 8
x + x + 3x^2 = 8
4x + 3x^2 = 8
3x^2 + 4x - 8 = 0

Now we have a quadratic equation which we can solve. Let's factor it:
(3x - 2)(x + 4) = 0

Setting each factor to zero gives us two possible solutions:
3x - 2 = 0
3x = 2
x = 2/3

x + 4 = 0
x = -4

Therefore, the solutions are x = 2/3 or x = -4.

Now, substitute these values back into the initial equation to find the corresponding values of y:
For x = 2/3:
3(2/3) + y = -1
2 + y = -1
y = -3

For x = -4:
3(-4) + y = -1
-12 + y = -1
y = 11

Therefore, the solutions to the system of equations are (2/3, -3) and (-4, 11).