Răspuns:
# x = (2 + sqrt (- 16)) / (2) #
# x = (2 sqrt (- 16)) / (2) #
Explicaţie:
De cand ------- #(-2)^2# - # (4 x x 1 x x 5) # <0, x are rădăcini imaginare
# x = (- b + - sqrt (b ^ 2 - (4ac)) / (2a)
# x = (- (- 2) + - sqrt ((- 2) ^ 2 - (4xx1xx5))) / (2xx1)
# x = (- (- 2) + - sqrt (4 - 20)) / (2) #
# x = (2 + sqrt (- 16)) / (2) #
# x = (2 sqrt (- 16)) / (2) #