What is the volume? Which option

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

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !