The graph of function $f$ passes through $(7,-1)$. Function $g$ satisfies $f(g(x)) = x$ and $g(f(x)) = x$ for all real numbers.

What point must the graph of $g$ pass through?

Someone me i need with this stuff

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

If 7x=9y, y/z = 7/5 , then x/z = (a) 2/7 (b) 7/9 (c) 9/5 (d) 9/7 (e) 5/9