In the morning, William drove to the store and used 1/2 of a gallon of gas. In the afternoon, he drove to the movie theater and used 5/6 of a gallon of gas. How much gas did William use in all?

Which of these statements is correct? the system of linear equations 6x - 5y = 8 and 12x - 10y = 16 has no solution. the system of linear equations 7x + 2y = 6 and 14x + 4y = 16 has an infinite number of solutions. the system of linear equations 8x - 3y = 10 and 16x - 6y = 22 has no solution. the system of linear equations 9x + 6y = 14 and 18x + 12y = 26 has an infinite number of solutions.