Alright, so here's your answer.
You start by making all the fractions into improper fractions.
[tex] 12\frac{1}{2} becomes \frac{25}{2} [/tex]
[tex]3 \frac{3}{5} becomes \frac{18}{5} [/tex]
and [tex] \frac{7}{4} [/tex] stays the same.
Now we have to find the least common denominator, which is 20. So we have to multiply each to get 20.
[tex] \frac{25}{2} becomes \frac{250}{20} [/tex]
[tex] \frac{18}{5} becomes \frac{72}{20} [/tex]
[tex] \frac{7}{4} becomes \frac{35}{20} [/tex]
Now we add all three, getting us [tex] \frac{357}{20} [/tex]
Simplify, and your answer is [tex]17 \frac{3}{4} [/tex]
Hope this helps!
