Help please I do not get this problem at all

Nick and nora are married and have three children in college. they have an adjusted gross income of 47,400. if their standard deduction is 12,600 itemized deductions are 14,200 and they get an exemption of 4000 for each adult and each dependent what is their taxable income

Find the domain of the following expression: 1/(√x)-2

Which best describes a central bank's primary goals? limiting inflation and reducing unemployment reducing unemployment and maintaining cash flow controlling stagflation and reducing unemployment managing credit and ensuring the money supply's liquidity