初中物理是关于自然规律的学科,除了简单的物理常识之外,也存在难度较大的计算题.作为中考的重要科目,初中物理的地位可想而知.在众多物理代数题中,代入法可在求代数值或解方程中应用,其效果明显,解题快捷、简便,加快了学生做题速度.一、代入法概述代入法的目的主要在于消元,常用在二元一次方程中,通过简单系数的选择,以未知数相互替代的方式来求解问题.通过代入法的运用,原有的二元一次方程化简为一元一次方程,这时,就可以求解一元一次方程.将求解得到值代入原有的二 Junior high school physics is a discipline on the laws of nature, in addition to simple physical common sense, there are difficult computational problems .As an important subject in senior high school physics can be imagined .In many physical algebra problems, into the law Can find algebraic value or solution equation, the effect is obvious, the problem is quick, simple, and speed up the students to do the question. First, the substitution method outlined The main purpose of substitution method is elimination, commonly used in the binary equation, Through the selection of simple coefficients, the problem can be solved by replacing each other by unknown numbers.Using the substitution method, the original binary linear equation is reduced to a unary linear equation, at this time, the linear equation can be solved, Substitute the original two