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Complete the square. Fill in the number that makes the polynomial given below, a perfect-square quadratic.x²-12x+

User Nantucket
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1 Answer

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We are given the first two terms x^2 - 12x and we need the third term to make it a perfect square trinomial.

A perfect square trinomial results from squaring a binomial. It is in the form:


(x+y)^2=x^2+2xy+y^2

So to find the third term, we divide the second term by twice the square root of the first term.

Square root of the first term = x

Twice the square root of the first term = 2x

Second term = -12x


(-12x)/(2x)=-6

Then, we square the answer.


(-6)^2=36

The third term, then, must be 36.

User DavidR
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