Simplify (i)(3i)

$(i) (3 i)$

Multiply $(i) (3 i)$ .

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

$3 (i^{1} i)$

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

$3 (i^{1} i^{1})$

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

$3 i^{1 + 1}$

Add $1$ and $1$ .

$3 i^{2}$

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

$3 \cdot - 1$

Multiply $3$ by $- 1$ .

$- 3$