Can someone help me in number 6 please

Which letters from the table represent like terms? a and b b and c a and d b and d

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

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq