Algebra Examples

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

Step 1

To write a polynomial in standard form, simplify and then arrange the terms in descending order.

$f (x) = a x^{2} + b x + c$

Step 2

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

Tap for more steps...

Step 2.1

Apply the distributive property.

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

Step 2.2

Apply the distributive property.

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

Step 2.3

Apply the distributive property.

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

Step 3

Simplify terms.

Tap for more steps...

Step 3.1

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

Tap for more steps...

Step 3.1.1

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

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

Step 3.1.2

Subtract $4 x$ from $4 x$ .

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

Step 3.1.3

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

$f (x) = x \cdot x - 4 \cdot 4$

Step 3.2

Simplify each term.

Tap for more steps...

Step 3.2.1

Multiply $x$ by $x$ .

$f (x) = x^{2} - 4 \cdot 4$

Step 3.2.2

Multiply $- 4$ by $4$ .

$f (x) = x^{2} - 16$