(2sqrt (7) + 3sqrt (2)) (sqrt (7) - 5sqrt (2)) คืออะไร

ตอบ:

# - (16 + 7sqrt14) #

คำอธิบาย:

# (2 * sqrt (7) + 3 * sqrt (2)) * (sqrt (7) - 5 * sqrt (2)) #

# = 2sqrt7 ^ * 2-10sqrt7 sqrt2 + 3sqrt2 * sqrt7-15sqrt2 ^ 2 #

# = 2 * * * * * * * * 7-7sqrt2 sqrt7-15 * 2 #

# = 14-30-7sqrt (2 * 7) #

# = - 16-7sqrt14 #

หรือ:

# = - (16 + 7sqrt14) #