Question

Which choice is equivalent to the expression below?

√-125

A. 5i√5

B. -5i

C. 5i√-5

D. 5i

E. √125

Answer 1

5i√5

Explanation:

Remark

125 factors

It is factored into 5*5*5

The rule for √5*5*5 is that two can be taken outside the square root sign. I is placed in front of the root sign like 5√ and the other 5 is thrown away.

The remaining 5 is left under the root sign

As usual

√-1 is i is taken outside the root sign

Solution

5i √5 is what you get.