(Sqrt (3)) / (sqrt (3)) sqrt (5+) sqrt (3) (3-) sqrt (5))?

Jawapan:

#2/7#

Kami ambil, # A = (sqrt5 + sqrt3) / (sqrt3 + sqrt3 + sqrt5) - (sqrt5-sqrt3) / (sqrt3 + sqrt3-sqrt5) #

# = (sqrt5 + sqrt3) / (2sqrt3 + sqrt5) - (sqrt5-sqrt3) / (2sqrt3-sqrt5) #

(= sqrt5-sqrt3) - (sqrt5-sqrt3) (2sqrt3 + sqrt5)) / ((2sqrt3 + sqrt5)

# = ((2sqrt15-5 + 2 * 3-sqrt15) - (2sqrt15 + 5-2 * 3-sqrt15)) / ((2sqrt3) ^ 2- (sqrt5) ^ 2)

# = (batalkan (2sqrt15) -5 + 2 * 3cancel (-sqrt15) - membatalkan (2sqrt15) -5 + 2 * 3 + cancel (sqrt15)) / (12-5)

#=(-10+12)/7#

#=2/7#

Perhatikan bahawa, jika dalam penyebutnya adalah

# (sqrt3 + sqrt (3 + sqrt5)) dan (sqrt3 + sqrt (3-sqrt5)) #

maka jawapannya akan berubah.