Answer:
Explanation:
To solve the system of equations:20x + 4y = 168x + y = 18, we can use substitution or elimination method.Substitution method:We can solve one equation for one variable, substitute the expression into the other equation, and solve for the other variable.x + y = 18 -> y = 18 - xSubstituting y into the first equation:20x + 4(18 - x) = 168Simplifying the equation:20x + 72 - 4x = 168Solving for x:16x = 96x = 6Substituting x back into the equation y = 18 - x:y = 18 - 6y = 12Therefore, the solution to the system of equations is (x, y) = (6, 12).Elimination method:We can multiply the second equation by 4, so that the y variable in the second equation will be eliminated when added to the first equation.20x + 4y = 1684x + 4y = 72 (multiplied by 4)Simplifying the equations:20x + 4y = 1684x + 4y = 72Subtracting the second equation from the first equation:16x = 96x = 6Substituting x back into the equation x + y = 18:y = 18 - 6y = 12Therefore, the solution to the system of equations is (x, y) = (6, 12).