Given data:
The given equation is -8x+x+15=-7x+12.
The given equation can be written as,
[tex]\begin{gathered} -8x+x+15=-7x+12 \\ -7x+15=-7x+12 \\ 15=12 \end{gathered}[/tex]The above expression is false.
Thus, there is no value of x, so the answer is ϕ.
