1. Deformation: According to the least common multiple of the coefficient of the unknown quantity (the same unknown quantity) with smaller absolute value, multiply the two sides of the equation by appropriate numbers to make the coefficient of one unknown quantity in the two equations equal or opposite, and then eliminate the unknown quantity by addition and subtraction.

Special reminder: When selecting the elimination object, it is best to choose the unknown number with opposite coefficient, equal coefficient, multiple or prime number as the elimination object.

2. Addition and subtraction: when the coefficients of the same unknown in the two equations are opposite, directly add the two equations; When the coefficients of the same unknown are equal, the two equations are subtracted, thus eliminating an unknown and transforming binary linear equations into univariate linear equations.

Special attention: when adding and subtracting two equations, you must add and subtract both sides of the equal sign of the two equations respectively, and pay attention to the changes of various symbols.

3. Solution: Solve the one-dimensional linear equation after elimination and find the value of another unknown.

4. Substitution: Substitute the value of the unknown quantity into a simpler equation in the set of equations, so as to find the value of another unknown quantity.

Fifth, writing solution: put two unknowns together with braces.

Binary linear equation: "An integral equation with two unknowns and the number of terms of the unknowns is 1 is called a binary linear equation. All binary linear equations can be reduced to the general formula of ax+by+c=0(a, b≠0) and the standard formula of ax+by=c(a, b≠0), otherwise it is not a binary linear equation group. "