3. (10 points) ???? a + bi ? ??? ?? ?? a ? b ? ???? ? x2--1 ? ?? ????. ???a + bi ?? a ? real part ?? ??? b ? imaginary part ?? ???. ? ??? z = al + bi ?.y-a2 +bz? ? ??? ?? (x + y) ? ?? (z x y) ? ??? ?? ????. A complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation 21. For the complex number a +bi, a is called the real part, and b is called the imaginary part. For two complex numbers z a tbyi a+bei, the addition (+ v) and the multiplication ( x y) are defined as follows