Given:-
[tex]\begin{gathered} 8+j=15 \\ \end{gathered}[/tex]To Find:-
The value of j.
To find the value of j, we need to keep j at one side of the equal to sign and take all other number to the other side of the equal to sign.
[tex]\begin{gathered} 8+j=15 \\ j=15-8 \\ j=7 \end{gathered}[/tex]So now the value of j has been found. The value of j is 7.