Answer: 
Step-by-step explanation:
Least Common Multiple :The least positive number that is a multiple of two or more numbers.
To find : The least common multiple of:
and 
Since, 

The least common multiple of:
and
=
[take highest power of x and y ]
Hence, the least common multiple of:
and
= 
Yes, a set of rational numbers include the set of integers
Answer: PQ=15
Step-by-step explanation:
XY=(PQ+SR)/2
PQ+SR=2*XY
PQ+35=2*25
PQ+35=50
PQ=15
Answer:
correct. the mean of 72 and 89 is 80?5
Step-by-step explanation:
find the mean to confirm it.
(a+b)/2
72+89= 161
161/2=80.5