8
5
-8i
Not necessarily, take for example the equation x^2=5-12i. Then, 3-2i satisfies the equation. However, 3+2i does not because (3+2i)^2 = 5+12i.
(-2 + 3i) + (-1 - 2i) = -2 + 3i - 1 - 2i = -2 - 1 + 3i - 2i = -3 + i
the conjugate 7-2i
It is 3 minus 2i
8
2i+6
7 + 2i
5
The conjugate of a complex number can be found by multiplying the imaginary part by -1, then adding the "real" part back. (-2i) * -1 = 2i, so the conjugation is 7+2i
0.6-2i?
It is 6+2i. But -6-2i will also serve.
There are infinitely many solutions for this. For example: 6 - 0 7 - 1 8 - 2 6.5 - 0.5 5 - (-1) (8 + 2i) - (2 + 2i) etc.
Multiply the numerator and denominator by the complex conjugate of the denominator ... [ root(2) minus i ]. This process is called 'rationalizing the denominator'.
-8i