# How do you perform the operation and write the result in standard form given (8+sqrt(-18))-(4+3sqrt2i)?

Aug 31, 2016

$\left(8 + \sqrt{- 18}\right) - \left(4 + 3 \sqrt{2} i\right) = 4$

#### Explanation:

While dealing with complex numbers always remember ${i}^{2} = - 1$ and $\sqrt{- 1} = i$.

Hence, $\left(8 + \sqrt{- 18}\right) - \left(4 + 3 \sqrt{2} i\right)$

= (8+sqrt(3×3×2×(-1)))-(4+3sqrt2 i)

= $8 + 3 \sqrt{2} i - 4 - 3 \sqrt{2} i$

= $4$