What is the midpoint for the pairs for number 1 and 2

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.

The length of the line segment ac is 8x-9 what is the value of x

In a rectangle klmn, km = 6x + 16 and ln = 49. find the value of x