1. If you just add these two together, they are going to cancel out.

만약 이 두개를 더하기만 한다면,

2. The left- hand side, these guys cancel out, that was the whole point, so you're just left with the absolute value of y as being less than or equal to.

|y|만 남았습니다 |y|가 우변보다 작거나 같습니다