How to solve simultaneous equations (addition andsubtraction method) 連立方程式の解き方 (加減法) - 令和義塾🛡中高生・高卒生・教員・留学志望者のための学習塾

Question: Let's solve the following simultanoues equations by the addition and subtraction method.

① 4x-3y=6 　　 ② 3x+2y=13

How to solve: A combination of 2 or more equations is called a simultaneous equation. The way to erase the letters by making equal the absolute values of the coefficients of the either letters of simultaneous equasion and adding or subtracting is called the addition and subtraction method. For this problem, to make equal the absolute value of the coefficient of y, we multiply the equation ① by 2 and the equation ② by 3. Then, you will find out x=3 --- ③. Substituting ③ into ①, y=2.