Precalculus Examples

$9 i (- 2 i + 9)$

Step 1

Apply the distributive property.

$9 i (- 2 i) + 9 i \cdot 9$

Step 2

Multiply $9 i (- 2 i)$ .

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Step 2.1

Multiply $- 2$ by $9$ .

$- 18 i i + 9 i \cdot 9$

Step 2.2

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

$- 18 (i^{1} i) + 9 i \cdot 9$

Step 2.3

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

$- 18 (i^{1} i^{1}) + 9 i \cdot 9$

Step 2.4

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

$- 18 i^{1 + 1} + 9 i \cdot 9$

Step 2.5

Add $1$ and $1$ .

$- 18 i^{2} + 9 i \cdot 9$

Step 3

Multiply $9$ by $9$ .

$- 18 i^{2} + 81 i$

Step 4

Simplify each term.

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Step 4.1

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

$- 18 \cdot - 1 + 81 i$

Step 4.2

Multiply $- 18$ by $- 1$ .

$18 + 81 i$