Direct variation can be written as a proportion. Therefore, we can write:

Cross multiply to get:
4y=40
Divide by 4 on both sides to get that
y=10.
:)
5=x
Step-by-step explanation:
Answers:
1.) 
2.) 
3.) 
4.) 
5.)
(That variable is a "v")
6.) 
7.) 
8.) 
9.) 
10.) 
(I answered the questions in order from top to bottom, hope I helped!)
Answer:
about 252 hope this helps! :)
Step-by-step explanation:
28 * 21 = 588
28 * 30 = 840
840 - 588 = 252