Question

Which choice is equivalent to the expression below?

Answer 1

B. 2i √5. To simplify √- 20 , it becomes √(-2)*(-2)*5, then √(-2)^5*5, which then becomes 2i because you cannot find the square root of a negative number. i means √-1, so √-20 is the same as 2i√5.

Answer 2

D) since
$\sqrt{ - 20} = \sqrt{ 4 \times - 5} = 2 \sqrt{ - 5} = 2 \sqrt{5 \times ( - 1)} = 2 \ \sqrt{5} i$