Answer:

Step-by-step explanation:
We are given an algebraic expression in two variables m and n as:

Now we are asked to evaluate this algebraic expression at :
m=21 and n=12
Hence, putting the values of m and n in algebraic expression we get:

Hence, the value of the expression is:

Answer: 6:30
Subtract 2 hours from 8:30 and it will give you your answer :)
Consider the function f(x). In the equation of f(x) you have to change the x to g(x) and f(x) to x, the order the equation to g(x). g(x) is the inverse function of the function f(x).