Răspuns:
# (Sqrt (10) -sqrt (5)) / (sqrt (10) + sqrt (5) = 3-2sqrt (2) #
Explicaţie:
# (Sqrt (10) -sqrt (5)) / (sqrt (10) + sqrt (5) #
#color (alb) ("XXX") = anula (sqrt (5)) / anula (sqrt (5)) * (sqrt (2) -1) / (sqrt (2) +1) #
#color (alb) ("XXX") = (sqrt (2) -1) / (sqrt (2) +1) * (sqrt (2) -1) / (sqrt (2) -1) #
#color (alb) ("XXX") = (sqrt (2) -1) ^ 2 / ((sqrt (2) ^ 2-1 ^ 2) #
#color (alb) ("XXX") = (2-2sqrt2 + 1) / (2-1) #
#color (alb) ("XXX") = 3-2sqrt (2) #