c933103 發問於 科學及數學數學 · 1 十年前

# Maths Question ask by junior secondary student

If x^(-n)*y^(-n)=z^(-n),

x,y and n are both nature number,

can z be nature number?

### 2 個解答

• 1 十年前
最愛解答

Choose x = y = z = 1,

L.H.S = 1 = R.H.S.

Theredore, if x,y and n are both nature number,

z can be nature number

2008-03-24 14:12:47 補充：

any real number(inculding natrue number) n satisfy the above proof

• hlyung
Lv 7
1 十年前

x^(-n)*y^(-n)=z^(-n)

(xy)^n=z^n

xy=z

if x,y and n are natural number, then z is also a natural number