Question 1085963
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-a = (2-3i) + (2+3i) = 4  ====>  a = -4.

b = (2-3i)*(2+3i) = {{{2^2 + 3^2}}} = 4 + 9 = 13.

====>  a + b = -4 + 13 = 9.


The Vieta's theorem.
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<U>Answer</U>. a + b = 9.