Question

when 9 is subtracted from the square of a number, the result is 8 times the number.Find the negative soulution.PLZ HELP FAST

Answer 1

Answer:

The negative solution  k = -1 is the desired solution.

Step-by-step explanation:

Let the given number = k

So, according to the question:

$k^{2} - 9 = 8k$

or, $k^{2} - 8k - 9 = 0$

Now, solving this quadratic equation, we get

$\implies k^{2} - 9k + k - 9 = 0$

or, k ( k-9) + 1 (k-9) = 0

⇒( k-9)(k+1)  = 0

or, ( k-9)  = 0 , or (k+1)  = 0

⇒  k  = 9  or  k  = -1

Since we only want the negative solution , the k = -1 is the desired solution.