Solve Using the Quadratic Formula 16x^2+40x+25=0

$16 x^{2} + 40 x + 25 = 0$

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 $a = 16$ , $b = 40$ , and $c = 25$ into the quadratic formula and solve for $x$ .

$\frac{- 40 \pm \sqrt{40^{2} - 4 \cdot (16 \cdot 25)}}{2 \cdot 16}$

Step 3

Simplify.

Simplify the numerator.

Raise $40$ to the power of $2$ .

$x = \frac{- 40 \pm \sqrt{1600 - 4 \cdot 16 \cdot 25}}{2 \cdot 16}$

Multiply $- 4 \cdot 16 \cdot 25$ .

Multiply $- 4$ by $16$ .

$x = \frac{- 40 \pm \sqrt{1600 - 64 \cdot 25}}{2 \cdot 16}$

Multiply $- 64$ by $25$ .

$x = \frac{- 40 \pm \sqrt{1600 - 1600}}{2 \cdot 16}$

Subtract $1600$ from $1600$ .

$x = \frac{- 40 \pm \sqrt{0}}{2 \cdot 16}$

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

$x = \frac{- 40 \pm \sqrt{0^{2}}}{2 \cdot 16}$

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

$x = \frac{- 40 \pm 0}{2 \cdot 16}$

$- 40$ plus or minus $0$ is $- 40$ .

$x = \frac{- 40}{2 \cdot 16}$

Multiply $2$ by $16$ .

$x = \frac{- 40}{32}$

Cancel the common factor of $- 40$ and $32$ .

Factor $8$ out of $- 40$ .

$x = \frac{8 (- 5)}{32}$

Cancel the common factors.

Factor $8$ out of $32$ .

$x = \frac{8 \cdot - 5}{8 \cdot 4}$

Cancel the common factor.

$x = \frac{8 \cdot - 5}{8 \cdot 4}$

Rewrite the expression.

$x = \frac{- 5}{4}$

Move the negative in front of the fraction.

$x = - \frac{5}{4}$

Step 4

The final answer is the combination of both solutions.

$x = - \frac{5}{4}$ Double roots