Solve Using the Quadratic Formula -x^2+10x-25=0

$- x^{2} + 10 x - 25 = 0$

Step 1

Use the quadratic formula to find the solutions.

$\frac{- b \pm \sqrt{b^{2} - 4 (a c)}}{2 a}$

Step 2

Substitute the values $a = - 1$ , $b = 10$ , and $c = - 25$ into the quadratic formula and solve for $x$ .

$\frac{- 10 \pm \sqrt{10^{2} - 4 \cdot (- 1 \cdot - 25)}}{2 \cdot - 1}$

Step 3

Simplify.

Simplify the numerator.

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

$x = \frac{- 10 \pm \sqrt{100 - 4 \cdot - 1 \cdot - 25}}{2 \cdot - 1}$

Multiply $- 4 \cdot - 1 \cdot - 25$ .

Multiply $- 4$ by $- 1$ .

$x = \frac{- 10 \pm \sqrt{100 + 4 \cdot - 25}}{2 \cdot - 1}$

Multiply $4$ by $- 25$ .

$x = \frac{- 10 \pm \sqrt{100 - 100}}{2 \cdot - 1}$

Subtract $100$ from $100$ .

$x = \frac{- 10 \pm \sqrt{0}}{2 \cdot - 1}$

Rewrite $0$ as $0^{2}$ .

$x = \frac{- 10 \pm \sqrt{0^{2}}}{2 \cdot - 1}$

Pull terms out from under the radical, assuming positive real numbers.

$x = \frac{- 10 \pm 0}{2 \cdot - 1}$

$- 10$ plus or minus $0$ is $- 10$ .

$x = \frac{- 10}{2 \cdot - 1}$

Multiply $2$ by $- 1$ .

$x = \frac{- 10}{- 2}$

Divide $- 10$ by $- 2$ .

$x = 5$

Step 4

The final answer is the combination of both solutions.

$x = 5$ Double roots