Final answer:
To solve the system of equations by substitution, solve one equation for one variable and substitute it into the other equation. In this case, the solution is x = 7 and y = -35.
Step-by-step explanation:
To solve the system of equations by substitution, we need to solve one equation for one variable and substitute it into the other equation. In this case, we can solve the first equation, y = -5x, for y and substitute it into the second equation. Substituting -5x for y in the second equation, we get: -5x = -7x - 14. Solving for x, we get x = 7. Substituting x = 7 into the first equation, we get y = -5(7) = -35.
Therefore, the solution to the system of equations is x = 7 and y = -35.