Question

The result obtained by subtracting 84 from
the square of a natural number is same as
three times the sum of that number and
8. Find that natural number.

Answer 1

Let the number is p

p² – 84 = 3(p+8)

or, p² – 3p – 108 = 0

or, (p–12) (p+9) = 0

or, p = 12