HELP PLSSSSSSSSSSSSSS!!!!!!!!!!!!!! I will Give Brainlyest!!!

Answer:
[tex]\frac{21}{8}[/tex]
Step-by-step explanation:
[tex]6\frac{1}{4}=6+\frac{1}{4}=\frac{25}{4}\\\\3\frac{5}{8}=3+\frac{5}{8}=\frac{29}{8}\\[/tex]
finally
[tex]6\frac{1}{4}-3\frac{5}{8}=\frac{25}{4}-\frac{29}{8}=\frac{21}{8}[/tex]