harry is trying tq solve the equation y=2x^2 - x-6 using the quadratic formula he has made an error in one of the steps below

Hello:

y = 2x² - x - 6

y = 2 (x² - 1/2 x - 3)

y = 2 (x² - 1/2 x + 1/16 - 1/16 - 3)

y = 2 ((x - 1/4) ² - 49/16) ... the quadratic formula

y = 0 : (x - 1/4) ² - 49/16 = 0

(x - 1/4) ² - (7/4) ² = 0

(x - 1/4-7/4) (x - 1/4+7/4) = 0

(x - 2) (x + 3/2) = 0

x - 2 = 0 or x + 3/2 = 0

x = 2 or x = - 3/2