(x^2·e^x)/(x+2)^2的不定积分～

∫(x^2e^x)/(x+2)^2dx=∫e^x(x^2+4x+4-4x-8+4)/(x+2)^2dx=∫e^x(x+2)^2-4(x+2)+4)/(x+2)^2dx=∫e^x[(x+2)^2-4(x+2)+4]/(x+2)^2dx=∫e^x[1-4/(x+2)+4/(x+2)^2]dx=∫e^x-4e^x/(x+2)+4e^x/(x+2)^2dx=e^x-4∫e^x/(x+2)dx...