Answers

  • Brainly User
2016-06-25T18:29:59+08:00
X = 15;  k =?

x² - k = 0
(15)² - k = 0
225 - k = 0
-k = -225
k = 225

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2016-06-25T18:40:01+08:00
First substitute the value of x

(15)^2-k=0
225-k=0
 
Then transpose the value of x which is 225 to the left hand side. Don't forget the sign when you're transposing. :)

-k= -225+0

-k= -225

Since the missing value is +K and not -K. Multiply both sides by negative 1 :)

(-1)(-k)= -225(-1)

k=225

You can also check your answer by substituting the value of x and the value of k.

(15)^2-225=0

225-225=0

0=0

Yay. The answer is correct if the value you've solved is equal to the equated value. I hope I could help. :)
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