The problem has an infinite number of solutions. A couple of them are (x, y) =
(4, 1)
(13, 5)
To find one of the solutions, pick a value for x or y, put it in the equation in place of the variable, and solve for the other variable by undoing the operations.
Example
Choose y = 1
4x - 9*1 = 7 (we put 1 where y was)
4x - 9 = 7 (perform the multiplication)
4x - 9 + 9 = 7 + 9 (undo the subtraction of 9 by adding 9 to both sides)
4x = 16 (perform the addition)
4x/4 = 16/4 (undo the multiplication by 4--by dividing both sides by 4)
x = 4 (perform the division)
(4, 1)
(13, 5)
To find one of the solutions, pick a value for x or y, put it in the equation in place of the variable, and solve for the other variable by undoing the operations.
Example
Choose y = 1
4x - 9*1 = 7 (we put 1 where y was)
4x - 9 = 7 (perform the multiplication)
4x - 9 + 9 = 7 + 9 (undo the subtraction of 9 by adding 9 to both sides)
4x = 16 (perform the addition)
4x/4 = 16/4 (undo the multiplication by 4--by dividing both sides by 4)
x = 4 (perform the division)