Your problem states that 325 people attended the theater that day, grossing \$2675 , at \$9 per ticket per adult ( x_1 )and \$7 per ticket per child ( x_2 ). This means that \$9 times x_1 , the number of adults, plus \$7 times x_2 , the number of children, produced \$2675 , and that the total number...