



 
Hi Michael, A complex number written in standard form is $a + bi$ where $a$ and $b$ are real numbers. $a$ is called the real part and $b$ is called the imaginary part. You can add complex numbers by adding the real parts and adding the imaginary parts. Thus $(7 + 4i) + (3 + 9i) = (7  3) + (4 + 9)i = 4 + 13i.$ I hope this helps,  


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