Question 879342
Applying the Pythagorean theorem
x^2 + (x+7)^2 = (x+9)^2   |Expand
2x^2 + 14x + 49 = x^2 + 18x + 81
 x^2 - 4x -32 = 0
 (x - 8)(x+4) = 0,  x = 8 (negative solution tossed out for unit measure)
shorter leg : 8
longer leg: 15
Hypotenuse: 17