If alb= p/q, then (a+b)/b=(p+b)/q.
True
False

The given numbers are 13, 27, 81, 21,43, 48,23,39,45.

Square number is that number which is a perfect square means if you multiply a number by itself the number you obtained is a perfect square i.e it's square root is a natural number.

√13=not a natural number

√27=√3×√3×√3=3√3=irrational number

√81=√9×√9=9=a natural number

√21=not a natural number

√43=not a natural number

√48=4√3=not a natural number

√23=not a natural number

√39=not a natural number

√45=3√5=not a natural number

So, out of following numbers 13 27 81 21 43 48 23 39 45→81 is the only square number.