Precalculus Examples

$x^{2} = - 4 x - 4$

Step 1

Add $4 x$ to both sides of the equation.

$x^{2} + 4 x = - 4$

Step 2

Add $4$ to both sides of the equation.

$x^{2} + 4 x + 4 = 0$

Step 3

Factor using the perfect square rule.

Tap for more steps...

Step 3.1

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

$x^{2} + 4 x + 2^{2} = 0$

Step 3.2

Check that the middle term is two times the product of the numbers being squared in the first term and third term.

$4 x = 2 \cdot x \cdot 2$

Step 3.3

Rewrite the polynomial.

$x^{2} + 2 \cdot x \cdot 2 + 2^{2} = 0$

Step 3.4

Factor using the perfect square trinomial rule $a^{2} + 2 a b + b^{2} = {(a + b)}^{2}$ , where $a = x$ and $b = 2$ .

${(x + 2)}^{2} = 0$

Step 4

Set the $x + 2$ equal to $0$ .

$x + 2 = 0$

Step 5

Subtract $2$ from both sides of the equation.

$x = - 2$