To find the solution set of the given system of equations, we can use the method of substitution. First, we solve the first equation for y in terms of x: from the equation 4x = y, we rewrite it as y = 4x. Next, we substitute this expression for y into the second equation: substituting y = 4x into 2x - y = 0 gives us 2x - 4x = 0. Simplifying this, we get -2x = 0, which leads to x = 0. We also need to check for other values of x. Factoring out a common factor from the equation gives us 2x(x - 2) = 0, leading to x = 0 or x = 2. Now, substituting these x values back into the first equation to find y, we find that for x = 0, y = 4(0) = 0, giving us the point (0, 0). For x = 2, y = 4(2) = 8, giving us the point (2, 8). Therefore, the solution set of the system of equations is {(0, 0), (2, 8)}.