The second volume of the second day of junior high school mathematics authoritative examination paper
If the younger brother is X years old and the older brother is X years old when the younger brother is 1 year old, then the older brother is x- 1 year old; So my brother is 2x- 1 year old, and my brother is now (2x- 1)+(x- 1)=3x-2 years old; List the equation 3x-2=3 1 and get x= 1 1. So my brother is now 1 1 year old, and my brother is now 2 1 year old.