Math Problem Solver

18\left(\frac{500e^{-500x}}{1-e^{-500x}}\right)+13\left(\frac{1000e^{-1000x}-500e^{-500x}}{e^{-500x}-e^{-1000x}}\right)+7\left(\frac{1500e^{-1500x}-1000e^{-1000x}}{e^{-1000x}-e^{-1500x}}\right)-18000 = 0