If you're trying to solve for x, you need to use the quadratic formula.
[tex] \frac{-b+/- \sqrt{b^2 - 4(a)(c)} }{2a} [/tex]
Plug in the numbers from the standard form of a quadratic equation
(which is [tex]ax^2 + bx + c = 0[/tex])
[tex] \frac{34+/- \sqrt{34^2 - 4(16)(15)} }{2(16)} [/tex]
From here, this solves down to
[tex] \frac{34+/- \sqrt{196}}{32} [/tex]
Take the square root of 196, which is 14
[tex] \frac{34+/- 14}{32} [/tex]
Now, you can solve for both the + and - variations on the equation.
The solutions to your equation are 1.5 and 5/8 (probably)