How do you solve using the completing the square method $x^{2} + 2 x - 7 = 17$ $x^2+2x-7=17$ ?

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How do you solve using the completing the square method $x^{2} + 2 x - 7 = 17$ $x^2+2x-7=17$ ?

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Answer 1 · 2017-05-14T14:52:59

The solution is $x = 4 or x = - 6$ $x=4 or x=-6$ .

Explanation:

We have:

$x^{2} + 2 x - 7 = 17$ $x^2+2x-7=17$

Adding 8 to both sides completes the square on the left.

$x^{2} + 2 x + 1 = 25$ $x^2+2x+1=25$

Completing squares gives:

${(x + 1)}^{2} = 5^{2}$ $(x+1)^2=5^2$

Taking square roots gives:

$x + 1 = \pm 5$ $x+1=+-5$

This gives:

$x = 4 or x = - 6$ $x=4 or x=-6$

Answer 2 · 2017-05-14T14:53:36

${- 6; 4}$ ${-6;4}$

Explanation:

$x^{2} + 2 x - 7 = 17$ $x^2+2x−7=17$

$\Rightarrow x^{2} + 2 x + 1 = 25$ $=> x^2 +2x +1 = 25$
$\Rightarrow {(x + 1)}^{2} = 25$ $=> (x+1)^2 = 25$
$\Rightarrow x + 1 = 5$ $=> x+1 = 5$ or $x + 1 = - 5$ $x+1 =-5$
$\Rightarrow x = 4$ $=> x = 4$ or $x = - 6$ $x = -6$

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How do you solve using the completing the square method $x^{2} + 2 x - 7 = 17$ $x^2+2x-7=17$ ?

2 Answers

Explanation:

Explanation:

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How do you solve using the completing the square method x2+2x−7=17x^2+2x-7=17?

2 Answers

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How do you solve using the completing the square method $x^{2} + 2 x - 7 = 17$ $x^2+2x-7=17$ ?