11 is 97
12 is -7
13 is 75
14 is 2
15 is -40
I think there is a mistake in 16
17 is 13
18 is 5
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.
okay i dont know lololololokjdgshbnjhcdgsjfre
Answer:
-1/2
Step-by-step explanation:
Answer:
Perimeter: 18.5
Area: 15
Step-by-step explanation:
P = a + b + c
P = 5 + 6 + 7.5
P= 18.5
A = 1/2bh
A = 1/2*7.5*4
A= 15