Question

Using the quadratic formula to solve 4x^2 – 3x + 9 = 2x + 1, what are the values of x?

A: 1+-sqrt159i/8
B: 5+-sqrt153i/8
C: 5+-sqrt103i/8
D: 1+-sqrt153i/8

Answer 1

`4x^2-3x+9=2x+1 \\ 4x^2-3x-2x+9-1=0 \\ 4x^2-5x+8=0 \\ \\ a=4 \\ b=-5 \\ c=8 \\ b^2-4ac=(-5)^2 - 4 * 4 * 8=25-128=-103 \\ \\ x=(-b \pm √(b^2-4ac))/(2a)=(-(-5) \pm √(-103))/(2 * 4)=\boxed{(5 \pm √(103)i)/(8)}`

The answer is C.