You use the quadratic formula:
2x {}^{2} - 3x = 5
2x {}^{2} - 3x - 5 = 0
x = \frac{3 + - \sqrt{9 -4(2)( - 5)}}{2 \times 2}
x = \frac{3 + - \sqrt{49} }{4}
x = \frac{3 + 7}{4} \: and \: x = \frac{3 - 7}{4}
x = \frac{5}{2} \: and \: x = - 1
The square root of -17/16 is 0.257694102 i
