Simplifying Complex Expressions
This article will guide you through simplifying the expression (-7 + 3i)^2 + (-2 + 8i).
Understanding Complex Numbers
Complex numbers are numbers that can be expressed in the form a + bi, where a and b are real numbers, and i is the imaginary unit, defined as the square root of -1 (i.e., i² = -1).
Simplifying the Expression
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Expand the square:
- (-7 + 3i)² = (-7 + 3i)(-7 + 3i)
- Using the FOIL method (First, Outer, Inner, Last):
- (-7)(-7) + (-7)(3i) + (3i)(-7) + (3i)(3i)
- 49 - 21i - 21i + 9i²
- 49 - 42i - 9 (since i² = -1)
- 40 - 42i
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Combine the terms:
- (40 - 42i) + (-2 + 8i)
- (40 - 2) + (-42 + 8)i
- 38 - 34i
The Final Result
Therefore, the simplified form of the expression (-7 + 3i)² + (-2 + 8i) is 38 - 34i.