Geometry proofs question... I have no idea how to help my daughter with this problem!

Which statement describes the term economics? a. it is the study of using limited resources to fulfill wants and needs. b. it is the study of how governments fulfill the wants and needs of nations. c. it is the study of how people spend their money to fulfill wants and needs.

Which number produces a rationale number when multiplied by 1/5

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