The process of completing the squares, makes it possible to represent an expression as a square.
To complete the square on [tex]x^2 - 21x[/tex], add [tex]\frac{441}4[/tex]
The expression is given as:
[tex]x^2 - 21x[/tex]
The following steps would complete the square of [tex]x^2 - 21x[/tex].
First, ensure that the coefficient is [tex]x^2[/tex] is 1
Next, get the coefficient (k) of x
[tex]k = -21[/tex]
Divide by 2
[tex]\frac k2 = -\frac{21}2[/tex]
Square both sides
[tex](\frac k2)^2 = (-\frac{21}2)^2[/tex]
[tex](\frac k2)^2 = \frac{441}4[/tex]
This means that:
To complete the square, we simply need to add [tex]\frac{441}4[/tex] to the expression
Read more about completing squares at:
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