Solve Using the Quadratic Formula x^2-98=0

$x^{2} - 98 = 0$

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 $a = 1$ , $b = 0$ , and $c = - 98$ into the quadratic formula and solve for $x$ .

$\frac{0 \pm \sqrt{0^{2} - 4 \cdot (1 \cdot - 98)}}{2 \cdot 1}$

Step 3

Simplify.

Simplify the numerator.

Raising $0$ to any positive power yields $0$ .

$x = \frac{0 \pm \sqrt{0 - 4 \cdot 1 \cdot - 98}}{2 \cdot 1}$

Multiply $- 4 \cdot 1 \cdot - 98$ .

Multiply $- 4$ by $1$ .

$x = \frac{0 \pm \sqrt{0 - 4 \cdot - 98}}{2 \cdot 1}$

Multiply $- 4$ by $- 98$ .

$x = \frac{0 \pm \sqrt{0 + 392}}{2 \cdot 1}$

Add $0$ and $392$ .

$x = \frac{0 \pm \sqrt{392}}{2 \cdot 1}$

Rewrite $392$ as $14^{2} \cdot 2$ .

Factor $196$ out of $392$ .

$x = \frac{0 \pm \sqrt{196 (2)}}{2 \cdot 1}$

Rewrite $196$ as $14^{2}$ .

$x = \frac{0 \pm \sqrt{14^{2} \cdot 2}}{2 \cdot 1}$

Pull terms out from under the radical.

$x = \frac{0 \pm 14 \sqrt{2}}{2 \cdot 1}$

Multiply $2$ by $1$ .

$x = \frac{0 \pm 14 \sqrt{2}}{2}$

Simplify $\frac{0 \pm 14 \sqrt{2}}{2}$ .

$x = \pm 7 \sqrt{2}$

Step 4

The result can be shown in multiple forms.

Exact Form:

$x = \pm 7 \sqrt{2}$

Decimal Form:

$x = 9.89949493 \dots, - 9.89949493 \dots$