I would help but I'm not sure what you are asking for us to do
This isn’t 30 points this is 15
Answer:
Please see the attachments. For reasons I cannot fathom, the Brainly censor seems to think there are unapproved words contained in this text, so I cannot post it as text. Among other things, that means you probably will not be able to copy and paste the formulas into your spreadsheet—you will have to type them.
I apologize if you are offended by any of the words contained in this answer. I hope you will take them in the intended context—a math problem about the use of Excel.
Answer:

Step-by-step explanation:
All the angles in a triangle add up to 
Every right angle triangle has a right angle in it which is 
So to find the remaining angle, you do
-
-
= 
I think what you need to do is make B = -5
3a = -2(-5) - 7
3a = 10 - 7
3a = 3
a = 1