How do you reduce 64/100

Find the value of x. round the length to the nearest tenth

If f(x) and g(x) are inverse functions of each other, which of the following shows the graph of f(g(x)

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.