Find the real numbers x and y for which (2x - 3) + (y + 4)i = 5 + (2y - 1)i.

The number $i$ has $i^2 = -1$, and $\sqrt{-a} = \sqrt{a}\, i$ for $a > 0$. A complex number $a + ib$ has the real part $a$ and the imaginary part $b$, both real. Two complex numbers are equal only when their real parts are equal and their imaginary parts are equal.