中三數學law of indices

1.
0.0001
= 1/10000
= 1/10^4


2)
x^-2 ÷ x^3
= x^(-2-3)
= x^-5
= 1/x^5


3)
-(1 ÷ mn^2)
= -[m^(0-1) n^(0-2)
= -m^-1 n^-2
= -1/mn^2


4)
[(a^-2) b]^-1 (3a)^-1
= {a^[(-2)´(-1)] b^-1} (1/3)a^-1
= [a^2 b^-1] (1/3)a^-1
= (1/3) a^(2-1) b^-1
= (1/3) a b^-1
= a/3b


5)
2a^-1 + a^-2
= (2/a) + (1/a^2)
= (2a/a^2) + (1/a^2)
= (2a + 1)/a^2

1) 1X10^-4
2)X^-5
3)唔識.."
4)a/3b
5)1/a