What value for x makes this equation true? 9 • x = (9•10) + (9•3)

A. 3
B. 9
C. 10
D. 13

Can somebody me out with this question

Factor the expression using gcf 9b+45

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