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What is the intermediate step in the form (x + a)2 = b as a result of completing thesquare for the following equation?6x2 +962 - 13 = -132.Submit Answerattempt 1 out of 2

User Hammythepig
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1 Answer

19 votes
19 votes

First step is to separate the terms with variables from the constant terms.

Add 13 to both sides of the equation :


\begin{gathered} 6x^2+96x-13=-13 \\ 6x^2+96x-\cancel{13}+\cancel{13}=-13+13 \\ 6x^2+96x=0 \end{gathered}

Divide both sides by 6 :


\begin{gathered} 6x^2+96x=0 \\ x^2+16x=0 \end{gathered}

Next step, completing the square by adding this term to both sides of the equation :


((b)/(2a))^2

From the equation,

a = 1

b = 16

So it follows that :


((b)/(2a))^2=((16)/(2*1))^2=(8)^2

Adding this to both sides of the equation :


\begin{gathered} x^2+16x=0 \\ x^2+16x+8^2=8^2 \end{gathered}

And you will get a perfect square trinomial on the left side of the equation in the form :


x^2+bx+c^2

It can be factored as :


x^2+bx+c^2=(x+c)^2

So the equation will be :


\begin{gathered} x^2+16x+8^2=8^2 \\ (x+8)^2=8^2 \\ (x+8)^2=64 \end{gathered}

The answer is :


(x+8)^2=64

User Calebt
by
2.4k points
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