Square root of -25 show the value of this number in a+bi form

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

The number of branches on a tree demonstrates the fibonacci sequence. how many branches would there be on the next two levels of this tree? 13 | | | m branches

What numbers are included in the set of integers? what numbers are not included?