Simplify 3x^2-3(x-4)(x+4)

$3 x^{2} - 3 (x - 4) (x + 4)$

Step 1

Simplify each term.

Apply the distributive property.

$3 x^{2} + (- 3 x - 3 \cdot - 4) (x + 4)$

Multiply $- 3$ by $- 4$ .

$3 x^{2} + (- 3 x + 12) (x + 4)$

Expand $(- 3 x + 12) (x + 4)$ using the FOIL Method.

Apply the distributive property.

$3 x^{2} - 3 x (x + 4) + 12 (x + 4)$

Apply the distributive property.

$3 x^{2} - 3 x \cdot x - 3 x \cdot 4 + 12 (x + 4)$

Apply the distributive property.

$3 x^{2} - 3 x \cdot x - 3 x \cdot 4 + 12 x + 12 \cdot 4$

Simplify and combine like terms.

Simplify each term.

Multiply $x$ by $x$ by adding the exponents.

Move $x$ .

$3 x^{2} - 3 (x \cdot x) - 3 x \cdot 4 + 12 x + 12 \cdot 4$

Multiply $x$ by $x$ .

$3 x^{2} - 3 x^{2} - 3 x \cdot 4 + 12 x + 12 \cdot 4$

Multiply $4$ by $- 3$ .

$3 x^{2} - 3 x^{2} - 12 x + 12 x + 12 \cdot 4$

Multiply $12$ by $4$ .

$3 x^{2} - 3 x^{2} - 12 x + 12 x + 48$

Add $- 12 x$ and $12 x$ .

$3 x^{2} - 3 x^{2} + 0 + 48$

Add $- 3 x^{2}$ and $0$ .

$3 x^{2} - 3 x^{2} + 48$

Step 2

Simplify by adding terms.

Subtract $3 x^{2}$ from $3 x^{2}$ .

$0 + 48$

Add $0$ and $48$ .

$48$