Question 486209
Let x = shorter leg
 x^2 + (x +3)^2 = (2x - 3)^2 
x^2 + x^2 + 6x + 9 = 4x^2 -12x +9 
0 = 2x^2 -18x  
0 = 2x(x - 9) 
x = 9; this is the shorter leg.
12 is the longer leg.
15 is the hypotenuse.
9^2 + 12^2 = 15^2
81 + 144 = 225. 
This does check.
Cleomenius.