Perform Operations with Square Roots of Negative Numbers
Perform the indicated operations and write the result in standard form.
-$5 \sqrt { - 81 } + 3 \sqrt { - 4 }$
A) $51 \mathrm { i }$
B) $- 51$
C) 51
D) $- 51 \mathrm { i }$

Question

Quizplus · Accepted Answer

The square root of a negative number can be expressed using $i$, where $i = \sqrt{-1}$. Therefore, $5 \sqrt{-81} = 5 \cdot 9i = 45i$ and $3 \sqrt{-4} = 3 \cdot 2i = 6i$. Adding these together gives $45i + 6i = 51i$.

Perform Operations with Square Roots of Negative Numbers Perform the Indicated

Perform Operations with Square Roots of Negative Numbers
Perform the Indicated