The perimeter is the sum of all the sides so we can add all the sides and set it equal to 35:
[tex]x^2-2x+3x-4+x+2+x+9=x^2+3x+7[/tex]
Now we have a quadratic so we can use the quadratic formula to find x=[tex] \frac{-3+i \sqrt{19} }{2} [/tex]. Now you can plug that into each x to find each side:-)