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 variable x represents the number of . The variable y represents the number of . If y = 9, find the value of x. The committee needs square tables.