So with this, we will be using proportions. To solve for x, our proportion will be 
Firstly, cross-multiply: 
Next, subtract 36 on both sides: 
Next, replace -9x with 3x-12x 
Next, factor x^2+3x and -12x-36 separately:
. After, rewrite it as 
Next, solve for x separately in the two parentheses:


Since we can't have a negative length, x = 12.
To solve for y, our proportion will be 
Firstly, cross-multiply: 
Next, just square root each side, and your answer will be (rounded to hundredths) 
In short, x = 12 and y = 10.39.