excel 函数关于年终奖个人所得税计算的问题

这个公式能详细解释下吗？我研究了半天都知道怎么算出的`那个数字。请大家帮帮我！=ROUND(IF((O8+P8-(3500-R8))&#47;12<=0,0,IF((O8+P8-(3500-R8))&#47;12<=1500,((O8+P8-(3500-R8)))&#47;12*3%,IF((O8+P8-(3500-R8))&#47;12<=4500,((O8+P8-(3500-R8)))&#47;12*10%-105,IF((O8+P8-(3500-R8))&#47;12<=9000,((O8+P8-(3500-R8)))&#47;12*20%-555,IF((O8+P8-(3500-R8))&#47;12<=35000,((O8+P8-(3500-R8)))&#47;12*25%-1005,IF((O8+P8-(3500-R8))&#47;12<=55000,(((O8+P8-(3500-R8)))&#47;12*30%-2755),IF((O8+P8-(3500-R8))&#47;12<=80000,((O8+P8-(3500-R8)))&#47;12*35%-5505,((O8+P8-(3500-R8)))&#47;12*45%-13505)))))))*12,2)