Question:
The sum of the squares of two consecutive positive integers is 365. Find the integers.
Solution:
Let the required two consecutive positive integers be x and (x + 1).
According to the given condition,
$x^{2}+(x+1)^{2}=365$
$\Rightarrow x^{2}+x^{2}+2 x+1=365$
$\Rightarrow 2 x^{2}+2 x-364=0$
$\Rightarrow x^{2}+x-182=0$
$\Rightarrow x^{2}+14 x-13 x-182=0$
$\Rightarrow x(x+14)-13(x+14)=0$
$\Rightarrow(x+14)(x-13)=0$
$\Rightarrow x+14=0$ or $x-13=0$
$\Rightarrow x=-14$ or $x=13$
∴ x = 13 (x is a positive integer)
When x = 13,
x + 1 = 13 + 1 = 14
Hence, the required positive integers are 13 and 14.