Question

Hi, can you please help me answer this direct proportion question?

Somehow I keep getting it wrong and so I'd really appreciate some help. Please don't offer joke answers and possibly show me any workings out.
Thank you :)

Answer 1

X = 100

Explanation:

• In proportion questions, they want you to multiply one of the sides by a variable, (i usually represent it with K) and then change the proportion sign to an equal.
• This is because proportional means they have a ratio between them, with one side increasing by "k" for each increase in the other side.

1. Multiply the left by k, so
   `y = (k)/(√(x) )`
2. we know that y= 5, for x = 36, so sub this in the equation
3. 
   `5 = (k)/(√(36) )`
4. simplify
   `5 = (k)/(6 )`
5. re-arrange for k, k = 5*6 = 30
6. now we know k, we can create the real equation,
   `y = (30)/(√(x) )`
7. sub in 3 as y
8. 
   `3 = (30)/(√(x) )`
9. x = 100