Final answer:
To find the solution to a system of equations by substituting, you need to plug in the given values for x and y into each equation and solve for the unknown variables.
Step-by-step explanation:
Given a system of equations, we can find the solution by substituting the given values for x and y into each equation and checking if the resulting statement is true. The correct equation to use depends on the specific system of equations provided. Without the equations, we cannot determine the best equation to use or solve for y.
For example, if the system of equations is y = 9 + 3x and x = 5, we can substitute x = 5 into the equation y = 9 + 3x to find y = 9 + 3(5) = 9 + 15 = 24. Therefore, (x, y) = (5, 24) is a solution to the system of equations.