[tex]a) \: 3 + 4i \: = 3 - 4i \\b)1 + i \sqrt{3 \: } = 1 - \sqrt{3i} \\ c)1 - \sqrt{3i} = 1 + i \sqrt{3} \\ d) \frac{1 - i}{1 + i} = \frac{(1 - i) {}^{2} }{1 - i {}^{2} } = \frac{1 - 2i + i {}^{2} }{1 - ( - 1)} = \frac{1 - 2i - 1}{1 + 1} = \frac{ - 2i}{2} = - i [/tex]
