9514 1404 393
Explanation:
Subtraction is the same as adding the opposite. The difference of fractions with the same denominator is the difference of the numerators expressed over their common denominator.
[tex]\dfrac{12}{13}+\left(\dfrac{-1}{13}\right)\\\\=\boxed{\dfrac{12}{13}}-\boxed{\dfrac{1}{13}}\\\\=\boxed{\dfrac{11}{13}}[/tex]
