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I need help with my khan academy, I don't understand anything and it's hard to do my work..​

I need help with my khan academy, I don't understand anything and it's hard to do-example-1

2 Answers

5 votes

Answer:

(x - 7)² = 9

Explanation:

x² - 14x + 40 = 0 ( subtract 40 from both sides )

x² - 14x = - 40

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 7)x + 49 = - 40 + 49

(x - 7)² = 9

User Sri Reddy
by
3.2k points
5 votes

Answer:


\sf (x-\boxed{\bf7}\:)^2=\boxed{\bf9}

Explanation:

First of all, let's move the constant term to the right side of the equation:-


\sf x^(2) -14=-40

To complete the square we'll take half of the coefficient of our x term, square it, and add it to both sides of the equation. Since the coefficient of our x term is -14 ,half of it would be -7 and squaring it gives us 49.


\sf x^2-14x+49=-40+49

Now, we can rewrite the left side of the equation as a squared term.


\sf (x-7)^2=9

_____________________

Hope this helps!

Have a great day!

User Joz
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3.2k points