Answer
(a) 5
(b) $-3-4i$
(c) $3-4i$
Work Step by Step
(a) $|3+4i|=\sqrt {3^{2}+4^{2}}=\sqrt {9+16}=\sqrt {25}=5$
(b) Finding the opposite of $3+4i$ involves multiplying the complex number by -1:
$-(3+4i)=-3-4i$.
(c) The conjugate of $3+4i$ is $3-4i$.
