Question.
Find two consecutive positive integers, sum of whose squares is 365.
Find two consecutive positive integers, sum of whose squares is 365.
Solution:
Let the consecutive positive integers be x and x + 1.
Given that $x^{2}+(x+1)^{2}=365$
$\Rightarrow x^{2}+x^{2}+1+2 x=365$
$\Rightarrow 2 x^{2}+2 x-364=0$
$\Rightarrow x^{2}+x-182=0$
$\Rightarrow x^{2}+14 x-13 x-182=0$
$\Rightarrow x(x+14)-13(x+14)=0$
$\Rightarrow(x+14)(x-13)=0$
Either $x+14=0$ or $x-13=0$
i.e., $x=-14$ or $x=13$
Since the integers are positive, $x$ can only be $13 .$
$\therefore x+1=13+1=14$
Therefore, two consecutive positive integers will be 13 and 14 .
Let the consecutive positive integers be x and x + 1.
Given that $x^{2}+(x+1)^{2}=365$
$\Rightarrow x^{2}+x^{2}+1+2 x=365$
$\Rightarrow 2 x^{2}+2 x-364=0$
$\Rightarrow x^{2}+x-182=0$
$\Rightarrow x^{2}+14 x-13 x-182=0$
$\Rightarrow x(x+14)-13(x+14)=0$
$\Rightarrow(x+14)(x-13)=0$
Either $x+14=0$ or $x-13=0$
i.e., $x=-14$ or $x=13$
Since the integers are positive, $x$ can only be $13 .$
$\therefore x+1=13+1=14$
Therefore, two consecutive positive integers will be 13 and 14 .