Simplify 3x^2(7x^2-9)

$3 x^{2} (7 x^{2} - 9)$

Step 1

Simplify by multiplying through.

Apply the distributive property.

$3 x^{2} (7 x^{2}) + 3 x^{2} \cdot - 9$

Simplify the expression.

Rewrite using the commutative property of multiplication.

$3 \cdot 7 x^{2} x^{2} + 3 x^{2} \cdot - 9$

Multiply $- 9$ by $3$ .

$3 \cdot 7 x^{2} x^{2} - 27 x^{2}$

Step 2

Simplify each term.

Multiply $x^{2}$ by $x^{2}$ by adding the exponents.

Move $x^{2}$ .

$3 \cdot 7 (x^{2} x^{2}) - 27 x^{2}$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$3 \cdot 7 x^{2 + 2} - 27 x^{2}$

Add $2$ and $2$ .

$3 \cdot 7 x^{4} - 27 x^{2}$

Multiply $3$ by $7$ .

$21 x^{4} - 27 x^{2}$