Given the expression:
[tex]-3x-8=10[/tex]to solve for x, first we have to move the constant -8 to the right side of the equation. By doing this, the constant will change its sign when it's on the other side:
[tex]\begin{gathered} -3x-8=10 \\ \Rightarrow-3x=10+8=18 \\ \Rightarrow-3x=18 \end{gathered}[/tex]Now, we need to move the -3 to the right side. Since it is multiplying the variable x, we need to move it to the other side doing its opposite operation: the division:
[tex]\begin{gathered} -3x=18 \\ \Rightarrow x=\frac{18}{-3} \end{gathered}[/tex]notice that we have a division of a positive number by a negative number, then the result will be a negative number as well:
[tex]\begin{gathered} x=\frac{18}{-3}=-6 \\ x=-6 \end{gathered}[/tex]therefore x=-6
