Simplifying Complex Expressions: (7-3i) + (x-2i)² - (4i + 2x²)
This article will guide you through simplifying the complex expression (7-3i) + (x-2i)² - (4i + 2x²) into the standard form a + bi.
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 (i² = -1).
Step-by-Step Simplification
-
Expand the Square: Begin by expanding the squared term (x - 2i)²: (x - 2i)² = x² - 4xi + 4i²
-
Substitute i²: Remember that i² = -1. Substitute this into the expanded term: x² - 4xi + 4i² = x² - 4xi - 4
-
Combine Terms: Combine all the terms: (7 - 3i) + (x² - 4xi - 4) - (4i + 2x²) = 7 - 3i + x² - 4xi - 4 - 4i - 2x²
-
Rearrange and Group: Rearrange the terms to group the real and imaginary parts: (7 - 4 - 2x²) + (-3i - 4i - 4xi) = (3 - 2x²) + (-7 - 4x)i
Final Result
Therefore, the simplified form of the complex expression (7-3i) + (x-2i)² - (4i + 2x²) is (3 - 2x²) + (-7 - 4x)i.
This is now in the standard form a + bi, where:
- a = 3 - 2x²
- b = -7 - 4x