How do you simplify 7sqrt(-36) + 4sqrt(-81)736+481?

2 Answers
Nov 15, 2015

0

Explanation:

sqrt"-36"-36 = 0
sqrt"-81"-81 = 0
The square root of a negative integer = 0
(7times×0) + (4times×0) = 0

Nov 15, 2015

78i78i

Explanation:

If x in RR and x>0, then sqrt(-x)=isqrtx, where i^2=-1 and i=sqrt(-1) in CC.

Therefore,

7sqrt(-36)+4sqrt(-81)=7*(6i)+4*(9i)

=42i + 36i

=78i