Answer:
[tex]-5\dfrac{31}{40}[/tex]
Step-by-step explanation:
Convert to improper fractions:
[tex]1\dfrac{1}{10}-6\dfrac78=\dfrac{1 \times10+1}{10}-\dfrac{6 \times8+7}{8}=\dfrac{11}{10}-\dfrac{55}{8}[/tex]
Make denominators the same:
[tex]\dfrac{11}{10}-\dfrac{55}{8}=\dfrac{11\times8}{10\times8}-\dfrac{55\times10}{8\times10}=\dfrac{88}{80}-\dfrac{550}{80}[/tex]
Therefore,
[tex]\dfrac{88}{80}-\dfrac{550}{80}=\dfrac{88-550}{80}=-\dfrac{462}{80}=-\dfrac{231}{40}[/tex]
Convert to mixed number:
[tex]-\dfrac{231}{40}=-5\dfrac{31}{40}[/tex]
