Find the Discriminant -x^2+10x-9=0

$- x^{2} + 10 x - 9 = 0$

Step 1

The discriminant of a quadratic is the expression inside the radical of the quadratic formula.

$b^{2} - 4 (a c)$

Step 2

Substitute in the values of $a$ , $b$ , and $c$ .

$10^{2} - 4 (- - 9)$

Step 3

Evaluate the result to find the discriminant.

Simplify each term.

Raise $10$ to the power of $2$ .

$100 - 4 (- - 9)$

Multiply $- 4 (- - 9)$ .

Multiply $- 1$ by $- 9$ .

$100 - 4 \cdot 9$

Multiply $- 4$ by $9$ .

$100 - 36$

Subtract $36$ from $100$ .

$64$