Simplify -4b(-3b-5)-5(-2b-3)

$- 4 b (- 3 b - 5) - 5 (- 2 b - 3)$

Simplify each term.

Apply the distributive property.

$- 4 b (- 3 b) - 4 b \cdot - 5 - 5 (- 2 b - 3)$

Rewrite using the commutative property of multiplication.

$- 4 \cdot - 3 b \cdot b - 4 b \cdot - 5 - 5 (- 2 b - 3)$

Multiply $- 5$ by $- 4$ .

$- 4 \cdot - 3 b \cdot b + 20 b - 5 (- 2 b - 3)$

Simplify each term.

Multiply $b$ by $b$ by adding the exponents.

Move $b$ .

$- 4 \cdot - 3 (b \cdot b) + 20 b - 5 (- 2 b - 3)$

Multiply $b$ by $b$ .

$- 4 \cdot - 3 b^{2} + 20 b - 5 (- 2 b - 3)$

Multiply $- 4$ by $- 3$ .

$12 b^{2} + 20 b - 5 (- 2 b - 3)$

Apply the distributive property.

$12 b^{2} + 20 b - 5 (- 2 b) - 5 \cdot - 3$

Multiply $- 2$ by $- 5$ .

$12 b^{2} + 20 b + 10 b - 5 \cdot - 3$

Multiply $- 5$ by $- 3$ .

$12 b^{2} + 20 b + 10 b + 15$

Add $20 b$ and $10 b$ .

$12 b^{2} + 30 b + 15$