2.3 oz per bag, so for x bags you have 2.3x oz total.
The total amount is given as 27.6 oz, so you have 27.6=2.3x.
set equation [tex]27.6=2.3x[/tex]
simplify by dividing both sides by 2.3 [tex]\frac{27.6}{2.3}=\frac{2.3x}{2.3}[/tex]
solution: [tex]x=\frac{27.6}{2.3}=12[/tex]