We need 16 in the given expression to create a perfect square trinomial.
Let us say the given expression is:
[tex]x^{2} +8x +k^2[/tex]...............(1)
We can rewrite the above expression as:
[tex]x^{2} +2*x*4 +k^2[/tex].........(2)
The square of a+b is a²+2ab+b².
If we compare (2) with [tex]a^{2} +2ab+ b^{2}[/tex]
We get, a =x, b = 4 and k²=b²
Since b=4
So, k² =4²
k² =16
Put the value of k² in (1)
We get the expression [tex]x^{2} +8x +16[/tex]
Therefore, We need 16 in the expression [tex]x^{2} +8x+....[/tex]to create a perfect square trinomial.
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