How do I work these questions out

Question one:

y = x + 3 (1)
y = -x + 2 (2)

Question two:

y = 3x + 4 (1)
y = 2x + 1 (2)

Add the equations to each other. Then you will have 2y=5 for the first set. Now you can find y which is 5/2 and use it in one of the original equations to find x.

In the second set you need to multiple the first equation by -1 which should give you: -y = -3x-4. Now add it to the second equation. -y plus y = 0; -3x plus 2x = -x; -4 plus 1 = -3. Now you have a new equation that states 0 = -x-3; if we add x to both sides we get x = -3. Now you can replace x with -3 in one of the original equations and solve for y. You should get y = -5.

Supposing these to be two examples of simultaneous equations:
In both cases set the two values of y equal to each other:

x + 3 = -x + 2
Combine like terms:
2x = -1
Divide by 2:
x = -1/2
Substitute this value for x into y = -x + 2 and solve for y:
y = -(-1/2) + 2 = 5/2

3x + 4 = 2x + 1
Combine like terms:
x = -3
Substitute this value for x into y = 2x + 1 and solve for y:
y = 2(-3) + 1 = -5