Use elimination or substitution. The pair x = 6, y = 0 satisfies both equations: substituting gives 18 in the first equation and 6 in the second. A solution of simultaneous equations is one ordered pair that makes both equations true at the same time. Substitution is a reliable check because it tests the chosen x and y values directly in each equation. If even one equation does not balance, the pair is not the solution. The correct answer is x = 6, y = 0, which matches the calculation or reasoning shown.