Put 4 where "a" is and do the arithmetic. [tex]12-\dfrac{a}{4}=12-\dfrac{4}{4}=12-1=11[/tex]
The value of the expression is 11.
_____ This is very different from [tex]\dfrac{12-a}{4}=\dfrac{12-4}{4}=\dfrac{8}{4}=2[/tex] In this latter case, parentheses are required when the expression is rendered using plain text: (12 -a)/4.
