數學(指數)

1

81*x = 27*2y

3^(4x)=3^(6y)

4x=6y

x=(3/2)y

x may be 2,then y is 3

2

(2^m)^2 / 8^m

=2^(2m)/2^(3m)

=2^(-m)

=1/2^m

3

(14^a)^3 = 2^b(7^b)

(14^a)^3 = 14^b

3a=b

a=(1/3)b

4

冇解, 出錯題

5

[3^(n+1)-3(3^n)] / 3(3^n+2)

=[ 3^(n+1)-3^(n+1)] / 3(3^n+2)

=0

or

3^(n+1)-3(3^n) / 3(3^n+2)

=3^(n+1)-(3^n) / (3^n+2)

=3^(n+1)-1 / 9