Multiplying Complex Numbers: (3-2i)(5+4i)
This article will guide you through the process of multiplying the complex numbers (3-2i) and (5+4i).
Understanding Complex Numbers
Complex numbers are numbers that can be expressed in the form a + bi, where:
- a and b are real numbers
- i is the imaginary unit, defined as the square root of -1 (i² = -1)
Multiplication Process
To multiply complex numbers, we use the distributive property (or FOIL method):
(3-2i)(5+4i) = (3)(5) + (3)(4i) + (-2i)(5) + (-2i)(4i)
Simplifying the Expression
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Multiply the terms:
- (3)(5) = 15
- (3)(4i) = 12i
- (-2i)(5) = -10i
- (-2i)(4i) = -8i²
-
Substitute i² with -1:
- -8i² = -8(-1) = 8
-
Combine the real and imaginary terms:
- 15 + 8 + 12i - 10i
-
Simplify:
- 23 + 2i
Conclusion
Therefore, the product of (3-2i) and (5+4i) is 23 + 2i.