-2x^2 + 8x - 5 = 0

-2x^2 + 8x = 5

x^2 - 4x = -2.5

x^2 - 4x + 4 = -2.5 + 4

x^2 - 4x + 4 = 1.5

(x - 2)^2 = 1.5

(x - 2^2 - 1.5 is the standard form. The vertex is upwards. The vertex is (2, 1.5)