The function g is defined by:

g(x)=(x+1)/(x-2);. x≠2 and x≠5

Find and simplify an expression for:

1)g²(x)

2)g`¹(x)

3) The function h is defined by:

h(x)=(ax+3)/x ; x≠0

Given that hg`¹(4)=6, calculate the value of a.