Respuesta :

Answer:

[tex]-8ab-a+8[/tex]

Step-by-step explanation:

[tex](-9ab-a+9)-(-ab+1)[/tex]

First, we have to expand

[tex]-9ab-a+9+ab-1[/tex]

The above is equivalent to...

[tex]-9ab+ab-a+9-1[/tex]

[tex]-8ab-a+8[/tex]