Question

有三个自然数A B C,以之A×B=30,B×C=35,A×C=42,求A×B×C是多少?急急急急急急急急急急急急急急急

Answer 1

(A*B)(B*C)(A*C)=(A*B*C)^2=30*35*42=44100
A*B*C的绝对值为210
又因为A*B、B*C、A*C均为正值，则A、B、C因同为正值或同为负值
则A*B*C=210或-210

Answer 2

A×B=30
B×C=35
C×A=42
三个式子相乘，可得
(A×B×C)²=30×35×42=5×6×5×7×6×7=(5×6×7)²
∴A×B×c=5×6×7=210

Answer 3

30×35×42=(5×6×7)×(5×6×7)
A×B×C=5×6×7=210

Answer 4

A×B=30,B×C=35,A×C=42
A=30/B C=35/B代入A*C=42
30/B*35/B=42
b^2=30*35/42=25
B=5
A=30/5=6
C=35/5=7
ABC=5*6*7=210

Answer 5

A^2*B^2*C^2=30*35*42
所以A*B*C就等于上面的开平方就等于210