To determine the solution(s) to the system of equations, we can solve for x and y.
First, we'll solve the first equation, y = 5x + 7, for y. By subtracting 5x from both sides, we get y = 5x + 7.
Now we'll substitute this expression for y into the second equation: 3y - 15x = 18.
Substituting y = 5x + 7, we get 3(5x + 7) - 15x = 18.
Expanding and simplifying this equation, we have 15x + 21 - 15x = 18, which simplifies to 21 = 18.
As 21 is not equal to 18, this equation is not true. This implies that there is no solution to the system of equations. Therefore, the system has no solution.