12. 90/15 is 6. 6x2 is 12.
8540 should be the standard notation
Did you mean to answer someone else’s question?
Answer:
I can't answer the whole question but the first one is 7 x 9, or 63 squares. And say you chose a square that is 4 x 3 so that would be the area of the tile you chose. Im sorry I couldn't answer the whole thing but I hope that makes since of what I did, if not please ask questions.
Step-by-step explanation:
Step-by-step explanation:
You said the other one would be the last haha just kidding I'm glad to help.
16. 
First, get rid of that parenthesis.

Now multiply both sides by 2 so that you can isolate k


19. 
This is a pretty easy one. If you didn't know, 121/11 is actually 11 :)

Simply multiply by 3 to isolate r :)

