Raspberry Pi no audio how to fix no audio in rpi

I reinstallled my rpi and got no audio out
The solution I found was:
1. install alsa utils by running the following command in the terminal:

sudo apt-get install alsa-utils

2. selecting the required audio out channel, where 0 is auto, 1 is phones and 2 is HDMI:

sudo amixer -c 0 cset numid=3 {out-number}