Algebra Examples

$2 x^{2} - 13 x = 1$

Step 1

Subtract $1$ from both sides of the equation.

$2 x^{2} - 13 x - 1 = 0$

Step 2

Use the quadratic formula to find the solutions.

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

Step 3

Substitute the values $a = 2$ , $b = - 13$ , and $c = - 1$ into the quadratic formula and solve for $x$ .

$\frac{13 \pm \sqrt{{(- 13)}^{2} - 4 \cdot (2 \cdot - 1)}}{2 \cdot 2}$

Step 4

Simplify.

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Step 4.1

Simplify the numerator.

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Step 4.1.1

Raise $- 13$ to the power of $2$ .

$x = \frac{13 \pm \sqrt{169 - 4 \cdot 2 \cdot - 1}}{2 \cdot 2}$

Step 4.1.2

Multiply $- 4 \cdot 2 \cdot - 1$ .

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Step 4.1.2.1

Multiply $- 4$ by $2$ .

$x = \frac{13 \pm \sqrt{169 - 8 \cdot - 1}}{2 \cdot 2}$

Step 4.1.2.2

Multiply $- 8$ by $- 1$ .

$x = \frac{13 \pm \sqrt{169 + 8}}{2 \cdot 2}$

Step 4.1.3

Add $169$ and $8$ .

$x = \frac{13 \pm \sqrt{177}}{2 \cdot 2}$

Step 4.2

Multiply $2$ by $2$ .

$x = \frac{13 \pm \sqrt{177}}{4}$

Step 5

The result can be shown in multiple forms.

Exact Form:

$x = \frac{13 \pm \sqrt{177}}{4}$

Decimal Form:

$x = 6.57603367 \dots, - 0.07603367 \dots$