f(g(x)) is a composition where g(x) is is substituted for x in f(x).
Recall, f(x) is 2/x. So we write 2/|x|-1. This places x in the denominator and 0 cannot be in the denominator x. Any value of x that makes the denominator 0 will not be in the domain.
Firstly, subtract the cost that Emil has already put down; 268.26-12= 256.26 Then divide by the monthly installments 256.26/ 6= 42.71 Therefore, Emil pays $42.71 per month Hope this helps :) <span />