Simplify -3x(7x+4y-10)

$- 3 x (7 x + 4 y - 10)$

Apply the distributive property.

$- 3 x (7 x) - 3 x (4 y) - 3 x \cdot - 10$

Simplify.

Rewrite using the commutative property of multiplication.

$- 3 \cdot 7 x \cdot x - 3 x (4 y) - 3 x \cdot - 10$

Rewrite using the commutative property of multiplication.

$- 3 \cdot 7 x \cdot x - 3 \cdot 4 x y - 3 x \cdot - 10$

Multiply $- 10$ by $- 3$ .

$- 3 \cdot 7 x \cdot x - 3 \cdot 4 x y + 30 x$

Simplify each term.

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

Move $x$ .

$- 3 \cdot 7 (x \cdot x) - 3 \cdot 4 x y + 30 x$

Multiply $x$ by $x$ .

$- 3 \cdot 7 x^{2} - 3 \cdot 4 x y + 30 x$

Multiply $- 3$ by $7$ .

$- 21 x^{2} - 3 \cdot 4 x y + 30 x$

Multiply $- 3$ by $4$ .

$- 21 x^{2} - 12 x y + 30 x$