12. Simplify the expression: \(2.4h \cdot 3i\)

To simplify the expression \(2.4h \cdot 3i\), we multiply the numerical coefficients and the variables separately.

Multiply the coefficients: \(2.4 \cdot 3 = 7.2\).

Multiply the variables: \(h \cdot i = hi\).

Combine the results: \(7.2hi\).

Ответ: \(7.2hi\)