Question

The product of two consecutive natural numbers is $56$. Find their sum.

Answer 1

$\Rightarrow$ Let two consecutive natural number be $x$ and $x+1$

According to the question,

$\Rightarrow$ $x(x+1)=56$

$\Rightarrow$ $x^2+x-56=0$

$\Rightarrow$ $x^2+8x-7x-56=0$

$\Rightarrow$ $x(x+8)-7(x+8)=0$

$\Rightarrow$ $(x+8)(x-7)=0$

$\Rightarrow$ $x=-8$ and $x=7$

Natural number can not be negative

$\therefore$ $x=7$

$\Rightarrow$ $x+1=7+1=8$

$\Rightarrow$ Required sum $=7+8=15$