I think I may be missing something ... I don't completely understand your question.
All you need to make a fraction is two numbers and a bar. The bar can be either
horizontal or slanty. Then you write one number on top and the other number on
the bottom, and bada-bing, you have a fraction.
You can make fractions like
2700 / 600
27 / 6
9 / 2 (all 3 of these have the same value)
600 / 2700
6 / 27
2 / 9 (all 3 of these have the same value)
The value of y=29
the value of x=61
Answer: 
Step-by-step explanation:
I hope you mean y = x² - 12 and not y = 2x - 12.
You switch the y and x variables:
x = y² - 12
And solve for y:
x + 12 = y²
The answer is the top one.
