Solve by Completing the Square (x^2)/2+3/2x=6

$\frac{x^{2}}{2} + \frac{3}{2} x = 6$

Step 1

Combine $\frac{3}{2}$ and $x$ .

$\frac{x^{2}}{2} + \frac{3 x}{2} = 6$

Step 2

Multiply each term in $\frac{x^{2}}{2} + \frac{3 x}{2} = 6$ by $2$ to eliminate the fractions.

Multiply each term in $\frac{x^{2}}{2} + \frac{3 x}{2} = 6$ by $2$ .

$\frac{x^{2}}{2} \cdot 2 + \frac{3 x}{2} \cdot 2 = 6 \cdot 2$

Simplify the left side.

Simplify each term.

Cancel the common factor of $2$ .

Cancel the common factor.

$\frac{x^{2}}{2} \cdot 2 + \frac{3 x}{2} \cdot 2 = 6 \cdot 2$

Rewrite the expression.

$x^{2} + \frac{3 x}{2} \cdot 2 = 6 \cdot 2$

Cancel the common factor of $2$ .

Cancel the common factor.

$x^{2} + \frac{3 x}{2} \cdot 2 = 6 \cdot 2$

Rewrite the expression.

$x^{2} + 3 x = 6 \cdot 2$

Simplify the right side.

Multiply $6$ by $2$ .

$x^{2} + 3 x = 12$

Step 3

To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of $b$ .

${(\frac{b}{2})}^{2} = {(\frac{3}{2})}^{2}$

Step 4

Add the term to each side of the equation.

$x^{2} + 3 x + {(\frac{3}{2})}^{2} = 12 + {(\frac{3}{2})}^{2}$

Step 5

Simplify the equation.

Simplify the left side.

Simplify each term.

Apply the product rule to $\frac{3}{2}$ .

$x^{2} + 3 x + \frac{3^{2}}{2^{2}} = 12 + {(\frac{3}{2})}^{2}$

Raise $3$ to the power of $2$ .

$x^{2} + 3 x + \frac{9}{2^{2}} = 12 + {(\frac{3}{2})}^{2}$

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

$x^{2} + 3 x + \frac{9}{4} = 12 + {(\frac{3}{2})}^{2}$

Simplify the right side.

Simplify $12 + {(\frac{3}{2})}^{2}$ .

Simplify each term.

Apply the product rule to $\frac{3}{2}$ .

$x^{2} + 3 x + \frac{9}{4} = 12 + \frac{3^{2}}{2^{2}}$

Raise $3$ to the power of $2$ .

$x^{2} + 3 x + \frac{9}{4} = 12 + \frac{9}{2^{2}}$

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

$x^{2} + 3 x + \frac{9}{4} = 12 + \frac{9}{4}$

To write $12$ as a fraction with a common denominator, multiply by $\frac{4}{4}$ .

$x^{2} + 3 x + \frac{9}{4} = 12 \cdot \frac{4}{4} + \frac{9}{4}$

Combine $12$ and $\frac{4}{4}$ .

$x^{2} + 3 x + \frac{9}{4} = \frac{12 \cdot 4}{4} + \frac{9}{4}$

Combine the numerators over the common denominator.

$x^{2} + 3 x + \frac{9}{4} = \frac{12 \cdot 4 + 9}{4}$

Simplify the numerator.

Multiply $12$ by $4$ .

$x^{2} + 3 x + \frac{9}{4} = \frac{48 + 9}{4}$

Add $48$ and $9$ .

$x^{2} + 3 x + \frac{9}{4} = \frac{57}{4}$

Step 6

Factor the perfect trinomial square into ${(x + \frac{3}{2})}^{2}$ .

${(x + \frac{3}{2})}^{2} = \frac{57}{4}$

Step 7

Solve the equation for $x$ .

Take the specified root of both sides of the equation to eliminate the exponent on the left side.

$x + \frac{3}{2} = \pm \sqrt{\frac{57}{4}}$

Simplify $\pm \sqrt{\frac{57}{4}}$ .

Rewrite $\sqrt{\frac{57}{4}}$ as $\frac{\sqrt{57}}{\sqrt{4}}$ .

$x + \frac{3}{2} = \pm \frac{\sqrt{57}}{\sqrt{4}}$

Simplify the denominator.

Rewrite $4$ as $2^{2}$ .

$x + \frac{3}{2} = \pm \frac{\sqrt{57}}{\sqrt{2^{2}}}$

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

$x + \frac{3}{2} = \pm \frac{\sqrt{57}}{2}$

Subtract $\frac{3}{2}$ from both sides of the equation.

$x = \pm \frac{\sqrt{57}}{2} - \frac{3}{2}$

Step 8

The result can be shown in multiple forms.

Exact Form:

$x = \pm \frac{\sqrt{57}}{2} - \frac{3}{2}$

Decimal Form:

$x = 2.27491721 \dots, - 5.27491721 \dots$

Solve by Completing the Square (x^2)/2+3/2x=6

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