Please Help

3n+4=7 |-4

    3n=3  |:3

      n=1

3n+4=7

1.take four from both sides

2.then divide both sides by three.

1. 3n=3

2. n=1

so n equals one

Take 7 minus 4, that is 3. So 3n has to bee equal to 3 and therefore n=1 because 1x3 = 3.