x^ 2 −x−20=0 completing the square

Question

the format the answer should be in is

(x+#)^2=#

Answer 1

x² - x = 20

x² - x + [(1/2)(-1)]² = 20 + [(1/2)(-1)]²

x² - x + 1/4 = 81/4

(x - 1/2)² = 81/4

x - 1/2 = ±9/2

x = 1/2 ± 9/2 = 5 or -4