The steps of solving binary linear equations by addition and subtraction;
① Using the basic properties of the equation, the coefficient of an unknown quantity in the original equation is transformed into an equal or opposite number.
(2) Using the basic properties of the equation, add or subtract the two deformed equations to eliminate an unknown number, and get a one-dimensional linear equation (both sides of the equation must be multiplied by the same number, and it is forbidden to multiply only one side. If the unknown coefficient is equal, it will be subtracted, and if the unknown coefficient is opposite, it will be added).
(3) Solve this one-dimensional linear equation and get the unknown value.
(4) Substituting the obtained value of the unknown quantity into any equation in the original equation to obtain the value of another unknown quantity.
To understand the solution of binary linear equation, we should pay attention to the following points:
Generally speaking, a binary linear equation has countless solutions, and each solution refers to a pair of values, not a single unknown value.
(2) A solution of a binary linear equation refers to a pair of unknowns whose left and right sides are equal; Conversely, if a set of values can make the left and right sides of a binary linear equation equal, then this set of values is the solution of the equation.
(3) When solving a binary linear equation, the usual practice is to use one unknown to represent another unknown, and then give this unknown a value, and correspondingly get the value of another unknown, so that a solution of the binary linear equation can be obtained.