Adult ticket=£17 and child ticket=£9 hope this helps
The answer should be 32 2/3. Sorry I'm late, but hope this helps.
First example:
Subtract the 8n on both sides to get the variable on one side of the equation. Do the same for the regular numbers. Then divide by -3.

This should be your final answer.
Second Example:
Do the same thing as explained in Example 1. Here's some work to help guide you.

That should be your final answer here.
Third Example:

Hope this helps and its understandable! Let me know if you still don't understand.
Substitute y = -x into the first equation:
-8x - 7(-x) = -5
-8x + 7x = -5
-x = -5
x = 5
Substitute x = 5 into y = -x
y = -(5)
y = -5
Answer: x = 5, y = -5