Respuesta :
You did not include any parenthesis, but I am assuming this is how the problem is supposed to look. Hope this helps.

a = -162
Work :
a -10 = 8
— +10 +10
-9
————————
a -9
— • — = 18 • -9 a = -162
-9 1
Work :
a -10 = 8
— +10 +10
-9
————————
a -9
— • — = 18 • -9 a = -162
-9 1