Would someone like to help me with 5 math problems?

Restrictions on f(x) = 1/x+5 and g(x) = x-2

Brady has a 20 year fixed rate mortgage for $215,500 with monthly payments of 1,305.89.the annual interest rate is 4%. what is the total cost of the principal and interest for this loan rounded to the nearest dollar

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number