Good Day,
Just wanted to ensure i did this question correctly, the question was to write the problem below in standard form. If incorrect any help to solve this question would be appreciated.
thanks in advance
Hello, netlab!
Your steps seem to be okay, but that $\displaystyle \sqrt{1}$ is unnecessary.
$\displaystyle 5\sqrt{\text{-}16} \:+ \:3\sqrt{\text{-}81}$
. . $\displaystyle = \;5\sqrt{(16)(\text{-}1)} \:+ \:3\sqrt{(81)(\text{-}1)} $
. . $\displaystyle = \;5\!\cdot\!\sqrt{16}\!\cdot\!\sqrt{\text{-}1} \:+ \:3\!\cdot\!\sqrt{81}\!\cdot\!\sqrt{\text{-}1} $
. . $\displaystyle = \;5\!\cdot\!4\!\cdot\!i \:+\: 3\!\cdot\!9\!\cdot\!i$
. . $\displaystyle =\;\;20i + 27i \;\;=\;\;\boxed{47i} $