Confirm that f and g are inverses by showing that f(g(x)) = x and g(f(x)) = x? f(x)=(x-7)/(x+2) and g(x)=(-2x-7)/(x-1)

A) if $50000 is invested in a bank account that pays 9.3% of interest compounded on a six-monthly basis, how much money will be in the account after 3 and 12 years? b) if matusalen's father had put $2.0 in the bank when he was born and there, how long would matusalen have had to his death (969 years later) if the interest was 7% per year composed each month and weekly?

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?