You are first going to put all like terms at one side and other like terms at the other side: 7+13=5y-y.
Next you will add like terms: 20=4y
Now you need to get the y by itself by dividing the 4 to both sides: 5=y and that would be your answer.
You should input the answer you get to make sure it’s correct:7=5(5)-13-5
Simplified all the way you would get: 7=7
This way you know that 5 is the correct answer for y.