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Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 2, Problem 47a

Find each sum or difference. Write answers in standard form. (3+2i) + (9+3i)

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Identify the problem as adding two complex numbers: \((3 + 2i)\) and \((9 + 3i)\).
Recall that to add complex numbers, you add their real parts together and their imaginary parts together separately.
Add the real parts: \$3 + 9$.
Add the imaginary parts: \$2i + 3i$.
Write the result in standard form as the sum of the real part and the imaginary part: \((\text{real part}) + (\text{imaginary part})i\).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Complex Numbers

Complex numbers are numbers in the form a + bi, where a and b are real numbers and i is the imaginary unit with the property i² = -1. They combine a real part and an imaginary part, allowing for operations beyond the real number line.
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Addition of Complex Numbers

To add complex numbers, add their real parts together and their imaginary parts together separately. For example, (a + bi) + (c + di) = (a + c) + (b + d)i, combining like terms to form a new complex number.
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Standard Form of Complex Numbers

The standard form of a complex number is written as a + bi, where a is the real part and b is the coefficient of the imaginary part. Writing answers in this form clearly separates the real and imaginary components.
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