Question 1006221
x, a leg's length;
-1+2x, the other leg's length;
{{{(2x-1)^2+x^2=17^2}}}


{{{4x^2-4x+1+x^2-17^2=0}}}
{{{5x^2-4x-289=0}}}


D for DISCRIMINANT;
{{{D=16+4*5*289=16+20*289=5796=9*644=9*4*161=6^2*161}}}


{{{x=(-4+- 6*sqrt(161))/10}}}

{{{highlight(x=(-2+3*sqrt(161))/5)}}}, and you can finish finding the other leg.