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1 vote
In order to complete the square for the equation below, what value should be added to both sides of the equation?

x2 - 8x + ? = 42 + ?

User Thedz
by
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1 Answer

6 votes

Answer:

? = 16

Explanation:

x2 - 8x + ? = 42 + ?

1. Take the coefficient of the middle term 8x, which is 8 and divide it by 2.
(8)/(2) = -4. Then square it
-4^(2) = 16

2. Take 16 and add it to both sides:
x^2 - 8x + 16 = 42 + 16

2. Take half of the coefficient 8 that you divided by 2, which is 4 and insert 4 into the equation
(x -4)^2 = 58

3. ? = 16

User HyLian
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4.7k points