Question

b. √(-8)·√(-18)

Explanation:

Step1: Rewrite with imaginary unit $i$

$\sqrt{-8} = i\sqrt{8}$, $\sqrt{-18} = i\sqrt{18}$

Step2: Multiply the two expressions

$i\sqrt{8} \cdot i\sqrt{18} = i^2 \cdot \sqrt{8 \times 18}$

Step3: Simplify $i^2$ and product inside root

$i^2 = -1$, $\sqrt{8 \times 18} = \sqrt{144} = 12$

Step4: Calculate final result

$-1 \times 12$

Answer:

$-12$