Step-by-step explanation:
[tex] = \frac{ |15 - 12| }{4} - | \frac{ - 21 + 9}{8} | [/tex]
[tex] = \frac{ |3| }{4} - \frac{ | - 12| }{ |8| } [/tex]
[tex] = \frac{3}{4} - \frac{12}{8} [/tex]
[tex] = \frac{3}{4} - \frac{6}{4} [/tex]
[tex] = - \frac{3}{4} [/tex]
Option → B
