Consider the production function \(q = f(x_1, x_2)\) where the firm produces \(q\) amount of output using \(x_1\) amount of factor 1 and \(x_2\) amount of factor 2. The firm decides to increase the employment level of both factors by \(t\) (\(t>1\)). Identify the equation for decreasing returns to scale from the following: