Worksheets — Set 17

Algebra II · Honors · Complex numbers (intro)

Print and write your answers. Use diagrams to show thinking.

Warm-up

1. (21 + 2i) + (19 − 5i) = ___ 2. (20i)(−1i) = ___ 3. Plot 20 − 3i on the complex plane. ___

_See printable PDF for diagram._

Written practice

1. (20 + 2i) + (18 − 5i) = ___ 2. (19i)(−3i) = ___ 3. Plot 19 − 4i on the complex plane. ___ 4. Multiply: (18 + i)(18 − i) = ___ 5. Solve x² + 21 = 0 in ℂ: x = ___ 6. Real part ___ , imaginary part ___ 7. (23 + 2i) + (21 − 5i) = ___ 8. (22i)(−3i) = ___

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More written practice

1. Plot 22 − 3i on the complex plane. ___ 2. Multiply: (21 + i)(21 − i) = ___ 3. Solve x² + 24 = 0 in ℂ: x = ___ 4. (26 + 2i) + (24 − 5i) = ___ 5. (25i)(−3i) = ___ 6. Plot 25 − 4i on the complex plane. ___

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Patterns and rules

1. (37 + 2i) + (35 − 5i) = ___ 2. (36i)(−2i) = ___ 3. Plot 36 − 3i on the complex plane. ___

_See printable PDF for diagram._

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Stretch

1. (45 + 2i) + (43 − 5i) = ___ 2. (44i)(−1i) = ___

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Parent tip: Combine like terms: real with real, imaginary with imaginary