Worksheets — Set 18

Algebra II · Honors · Complex numbers (intro)

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

Warm-up

1. (22 + 2i) + (20 − 5i) = ___ 2. (21i)(−2i) = ___ 3. Plot 21 − 4i on the complex plane. ___

_See printable PDF for diagram._

Written practice

1. (21 + 2i) + (19 − 5i) = ___ 2. (20i)(−1i) = ___ 3. Plot 20 − 3i on the complex plane. ___ 4. Multiply: (19 + i)(19 − i) = ___ 5. Solve x² + 22 = 0 in ℂ: x = ___ 6. Real part ___ , imaginary part ___ 7. (24 + 2i) + (22 − 5i) = ___ 8. (23i)(−1i) = ___

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More written practice

1. Plot 23 − 4i on the complex plane. ___ 2. Multiply: (22 + i)(22 − i) = ___ 3. Solve x² + 25 = 0 in ℂ: x = ___ 4. (27 + 2i) + (25 − 5i) = ___ 5. (26i)(−1i) = ___ 6. Plot 26 − 3i on the complex plane. ___

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Patterns and rules

1. (38 + 2i) + (36 − 5i) = ___ 2. (37i)(−3i) = ___ 3. Plot 37 − 4i on the complex plane. ___

_See printable PDF for diagram._

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Stretch

1. (46 + 2i) + (44 − 5i) = ___ 2. (45i)(−2i) = ___

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