Sam walked
[tex]2 \frac 1 5 \times 1 \frac 3 4 = \frac{11}{5} \times \frac{7}{4} = \frac{77}{20} \textrm{ miles}[/tex]
Lisa walked fewer miles, so we'll get a negative number for how many miles more Lisa walked.
[tex]\textrm{Lisa } - \textrm{ Sam } = \frac{11}{5} - \frac{77}{20} = \frac{44}{20} - \frac{77}{20} = - \frac{33}{20} = - 1 \frac{13}{20}[/tex]
Answer: -1 13/20 miles
