Answer:
[tex]\large\boxed{-\dfrac{7}{8}+\dfrac{3}{4}=-\dfrac{1}{8}}[/tex]
Step-by-step explanation:
To add two fractions we must have a common denominator.
[tex]8=4\cdot2[/tex]
Therefore
[tex]LCD=8[/tex]
[tex]-\dfrac{7}{8}+\dfrac{3}{4}=-\dfrac{7}{8}+\dfrac{3\cdot2}{4\cdot2}=-\dfrac{7}{8}+\dfrac{6}{8}=\dfrac{6}{8}+\left(-\dfrac{7}{8}\right)=\dfrac{6}{8}-\dfrac{7}{8}\\\\=\dfrac{6-7}{8}=\dfrac{-1}{8}=-\dfrac{1}{8}[/tex]