Simplify 15i*(-i-1)

$15 i \cdot (- i - 1)$

Step 1

Apply the distributive property.

$15 i (- i) + 15 i \cdot - 1$

Step 2

Multiply $15 i (- i)$ .

Multiply $- 1$ by $15$ .

$- 15 i i + 15 i \cdot - 1$

Raise $i$ to the power of $1$ .

$- 15 (i^{1} i) + 15 i \cdot - 1$

Raise $i$ to the power of $1$ .

$- 15 (i^{1} i^{1}) + 15 i \cdot - 1$

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

$- 15 i^{1 + 1} + 15 i \cdot - 1$

Add $1$ and $1$ .

$- 15 i^{2} + 15 i \cdot - 1$

Step 3

Multiply $- 1$ by $15$ .

$- 15 i^{2} - 15 i$

Step 4

Simplify each term.

Rewrite $i^{2}$ as $- 1$ .

$- 15 \cdot - 1 - 15 i$

Multiply $- 15$ by $- 1$ .

$15 - 15 i$