Someone please help me asnwer this!!

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39

Someone answer asap for ! the boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a. e = 2b - 212 b. b = 2e - 212 c. e = -2b + 212 d. b = -2e + 212