What is the answer to(5x+4)+(12x-9)

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.

Pls me this is due today and i need i will make brainliest if you me answer correctly and i will report if you try to give me a dumb answer.

The transitive property of equality states that: o if a = b, then bra o if a = b, then ac = bc o if a = b and b= c, then a = if a = b and c= c, then a + b = b + c