can I have some help? I don't understand this

Answer:
15
__
28
Step-by-step explanation:
just multiply top by bottom
5*3 15
___ = ____
7*4 28
Answer:
the answer is 15/28
Step-by-step explanation:
if you multiply the numerators 5 and 3, you get 15. then you have to multiply the denominators 7 and 4 to get 28