Answer
$a=13$
Work Step by Step
We start with the given equation: $-23=-2a-10+a$
We add $10$ to both sides of the equation: $-23+10=-2a+a$
Now, we combine like terms on both sides of the equation: $-13=-a$
Finally, we divide by $-1$ on both sides of the equation: $a=\frac{-13}{-1}=13$