Respuesta :

y = 2x² - 20x - 3

Δ = b² - 4.a.c
Δ = (-20)² - 4.(2).(-3)
Δ = 400 + 8
Δ = 408

x =  -b +- √Δ/2a
x = 20 +- 2√102/4
x = 10 +- √102/2