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.
Adding a comment so the other answerer can get Brainliest :)
Answer:
Whats the full question ?
Step-by-step explanation:
Answer:
6 mm
Step-by-step explanation:
Use the Pythagorean Theorem to solve for the unknown leg

Since we need to solve for a, we will manipulate the equation in terms of b and c → 
Here, b = 7 mm and c =
mm
Plugging these numbers into our equation gives us
→
=
= 6 mm
Answer:
789
Step-by-step explanation:
9+10(78)
9+10*78
9+780
789