Precalculus Examples

$x = 4$ , $x = - 4$

Since the roots of an equation are the points where the solution is $0$ , set each root as a factor of the equation that equals $0$ .

$(x - 4) (x - (- 4)) = 0$

Simplify.

Tap for more steps...

Expand $(x - 4) (x + 4)$ using the FOIL Method.

Tap for more steps...

Apply the distributive property.

$x (x + 4) - 4 (x + 4) = 0$

Apply the distributive property.

$x \cdot x + x \cdot 4 - 4 (x + 4) = 0$

Apply the distributive property.

$x \cdot x + x \cdot 4 - 4 x - 4 \cdot 4 = 0$

Simplify terms.

Tap for more steps...

Combine the opposite terms in $x \cdot x + x \cdot 4 - 4 x - 4 \cdot 4$ .

Tap for more steps...

Reorder the factors in the terms $x \cdot 4$ and $- 4 x$ .

$x \cdot x + 4 x - 4 x - 4 \cdot 4 = 0$

Subtract $4 x$ from $4 x$ .

$x \cdot x + 0 - 4 \cdot 4 = 0$

Add $x \cdot x$ and $0$ .

$x \cdot x - 4 \cdot 4 = 0$

Simplify each term.

Tap for more steps...

Multiply $x$ by $x$ .

$x^{2} - 4 \cdot 4 = 0$

Multiply $- 4$ by $4$ .

$x^{2} - 16 = 0$

Enter YOUR Problem