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Rewrite the equation by completing the square.
x^2 + 2x - 8 = 0

User Cpeddie
by
3.4k points

2 Answers

3 votes

Answer:


\boxed{\sf \ \ (x+1)^2-9=0 \ \ }

Explanation:

hello,

we can notice that


(x+1)^2=x^2+2x+1

so


x^2+2x=(x+1)^2-1

and then


x^2+2x-8=0\\<=> (x+1)^2-1-8=0\\\\<=> (x+1)^2=9\\<=> x+1=3 \ or \ x+1=-3\\<=> x=2 \ or \ x=-4\\

solutions are 2 and -4

hope this helps

User Fniessen
by
2.8k points
5 votes

the answers are actually 1 and 9.

User Sitifensys
by
3.9k points