In order to subtract mixed numbers, the easiest way to do it is to make them into improper fractions.
In order to do that, multiply the whole number by the denominator and add it to the numerator.
That would make 24 [tex] \frac{1}{2}[/tex] into [tex] \frac{49}{2} [/tex].
Also, it'd make 19 [tex] \frac{5}{8}[/tex] into [tex] \frac{157}{8} [/tex].
Now that they're both improper fractions, you need to make them have a common denominator in order to actually subtract them. You can do that by multiplying the numerator and denominator of [tex] \frac{49}{2} [/tex] by 4, to make it stay the same fraction, but have the same denominator as [tex] \frac{157}{8} [/tex].
[tex] \frac{49}{2} = \frac{196}{8} [/tex]
Now we can subtract them!
[tex] \frac{196}{8} - \frac{157}{8} = \frac{39}{8} [/tex] When subtracting fractions, only subtract the numerators. You don't subtract the denominators.