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What should be done to x^2 -8x to create a perfect square?

User Lafeber
by
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1 Answer

6 votes

Step 1:

Write the expression


x^2\text{ - 8x}

Step 2:


\begin{gathered} To\text{ make the expression a p}\operatorname{erf}ect\text{ square, find c from} \\ b^2\text{ = 4ac} \end{gathered}

Step 3:

a = 1 , b = -8 , c = ?

Next, find c


\begin{gathered} b^2\text{ = 4ac} \\ (-8)^2\text{ = 4 }*\text{ 1 }*\text{ c} \\ 64\text{ = 4c} \\ c\text{ = }(64)/(4) \\ c\text{ = 16} \end{gathered}

Final answer


\begin{gathered} To\text{ make } \\ x^2\text{ - 8x a p}\operatorname{erf}ect\text{ square , add 16} \\ x^2\text{ - 8x + 16} \end{gathered}

Answer = 16

User Pinemangoes
by
4.8k points