You have the following expression:

in order to simplify the previous expression, first simplify expression inside parenthesis:
(8² - 12)/(8)·11 next, multipy numbers on the denominator
= (8² -12)/88 next, simplify numerator
= (64 - 12)/88
= 52/88 simplify fraction
= 26/44
= 13/22
Hence, the simplified expression is 13/2213/