Hello!
Let's solve these questions to find the corresponding values.
First box:

Let's rewrite equation II (I'll just change the side of the values and their signal, to isolate one variable).

Now, where's Y, we will replace it with (3 -x) in the second equation.

Solving it, we'll obtain two values for x:
• x', = -5
,
• x", = 3
Now, let's calculate y' and y" by replacement:

So, the solution for the first box is:
{ {-5, 8}; {3, 0} }
Third box:

Let's solve it in a similar way:

So, we have:

Solving it, we'll obtain two values for x:
• x', = -2
,
• x", = 3
Finding y' and y" by replacement, we have:

So, the solution for the third box is:
{ {-2, 5}; {3, -5} }