MATH SMARTIES I WILL GIVE BRAINLIEST PLEASE HELP AND PLEASE GIVE AN EXPLANATION!!!!!!!!!!!!!!

Answer:
30 books on the shelf are Fiction.
Step-by-step explanation:
Hey!
There are 50 books on a shelf.
how many books on the shelf are Fiction?
==================================================================
MAKE AN EQUATION!
We know that there are three Categories: Fiction, Science Fiction, and Non Fiction.
Total- 50
⇒ 50 =
1/5 of 50 are SF
⇒ 50 = (1/5)(50)
3/10 of 50 are NF
⇒ 50 = (1/5)(50) + (3/10)(50) + x
--------------------------------------------------------------------------------------------------------------
SOLVE THE EQUATION!
(1/5)(50) + (3/10)(50) + x = 50
To Isolate X-
-Multiply and remove the parentheses..
⇒ 50/10 + 150/10 + x = 50
-Simplify.
⇒ 5 + 15 + x = 50
-Add Like Terms
⇒ 20 + x = 50
-Subtract 20 from both sides.
⇒ 20 + x - 20 = 50 - 20
-Simplify Right Hand Side.
⇒ x = 30
--------------------------------------------------------------------------------------------------------------
So, 30 books on the shelf are Fiction.
==================================================================
Hope I Helped, Feel free to ask any questions to clarify :)
Have a great day!
More Love, More Peace, Less Hate.
-Aadi x