关于等价转化肖东（江苏丰县宋楼中学２２１７３１）利用等价性原则（如充要条件、逆否命题与原命题等价、等价性法则规定等）对问题所施行的等价转化，能确保结果的正确无误．同样，在牢牢确立等价转化思想意识的前提下，恰如其分地利用某些非等价转化手段，也常使问题的... Concerning the equivalent transformation of Xiao Dong (Songlou Middle School, Feng County, Jiangsu Province, 221731) using the equivalence principle (such as the necessary and sufficient conditions, the inverse proposition and the original propositional equivalence, the equivalence rule, etc.) to carry out the equivalent transformation of the problem, Can ensure the correct result. Similarly, under the premise of firmly establishing the ideology of equivalence and conversion, the proper use of certain non-equivalent conversion methods often leads to problems...