Answer:
x=-1, y=-4
Explanation:
For this question, you can replace y in one equation with the second one.
This means x-3=7x+3.
From there, you subtract x from each side, giving -3=6x+3.
Subtracting 3 from each side makes it -6=6x.
Dividing both sides by 6 leaves x isolated, with a result of x=-1.
You can substitute the value of x into either equation to work out y. I'm using the first one, as it has smaller numbers.
This equation is now y=-1-3, which can be solved for y=-4.
**This content involves simultaneous equations, which you may wish to revise. I'm always happy to help!