Question

Solve the following equation $y^2-2y=5$ which number should be added in given equation therefore, equation becomes complete square.

Answer 1

$y^2-2y=5$

$\Rightarrow y^2-2y-5=0$

$\Rightarrow {(y-\frac{2}{2})}^2-\frac{{\left(2\right)}^2}{4}-5=0$

$\Rightarrow {(y-1)}^2-6=0$

From the above expression, we can say that $6$ should be added in given equation $(y^2-2y=5)$ so that the equation becomes complete square.

Hence the correct answer is $6$.