Question

Which expression is equivalent to sqrt -108 - sqrt -3

A) 5 sqrt 3i
B) 6 sqrt 3i
C) 7 sqrt 3i
D) 8 sqrt 3i

Answer 1

answer : Option A

`√(-108) - √(-3)`

first we simplify each square root

The value of square root (-1) = i, to remove negative inside the square root we use 'i'

`√(-108) =√(-36* 3)= 6i√(3)`

`√(-3) = i√(3)` (we cannot simplify square root (3))

`√(-108) - √(-3)`

`6i√(3) - i√(3)`

Both are like terms, so we subtract it

`5i√(3)`

`5√(3) i`

Answer 2

sqrt (-108) - sqrt (-3)

sqrt(-1) sqrt(108) - sqrt(-1) sqrt(3)

sqrt(-1)*sqrt(36)*sqrt(3)-sqrt(-1)sqrt(3)

sqrt(-1)sqrt(3) (6-1)

isqrt(3)5

5isqrt(3)

Choice A