You need to subtract everything to the left side and set it equal to zero. Combine like terms.
Then, the coefficient of x^2 is a, the coefficient of x is b, and the constant term is c.
4x^2 - 5 = 3x + 4
4x^2 - 3x - 5 - 4 = 0
4x^2 - 3x - 9 = 0
a = 4; b = -3; c = -9
[tex] x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a} [/tex]
[tex] x = \dfrac{-(-3) \pm \sqrt{(-3)^2 - 4(4)(-9)}}{2(4)} [/tex]