Add [tex]\left(\dfrac{b}{2}\right)^2[/tex] in the expression to make it perfect square.
Important information:
We know that,
[tex](x+y)^2=x^2+2xy+y^2[/tex]
[tex](x+y)^2=a^2+(2y)a+\left(\dfrac{2y}{2}\right)^2[/tex]
It means, we need to add the square of half of the coefficient of x in [tex]x^2+bx[/tex] to make it perfect square, i.e., [tex]\left(\dfrac{b}{2}\right)^2[/tex].
[tex]x^2+bx+\left(\dfrac{b}{2}\right)^2=\left(x+\dfrac{b}{2}\right)^2[/tex]
Therefore, add [tex]\left(\dfrac{b}{2}\right)^2[/tex] in the expression to make it perfect square.
Find out more about 'Completing the square' here:
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