Final answer:
The equation has one solution.
Step-by-step explanation:
The given equations are y = 15x - 45 and y = 12x + 18. To determine the number of solutions, we can compare the slopes of the equations. The slopes of the equations are 15 and 12, which are different. Therefore, the equations intersect at a single point and have one solution.
To confirm the answer, we can solve the equation 15x - 45 = 12x + 18. By subtracting 12x from both sides, we get 3x - 45 = 18. Next, adding 45 to both sides gives 3x = 63. Finally, dividing both sides by 3 gives x = 21. Since x has a unique value, the equation has one solution.