Is 4(3m+4)=2(6m+8) an identity or has no solution.

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.

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

Asap! i'm not good math and i'm lost.