Math Problem Statement

(3 + 4i)(2 - 2i)

Solution

The given expression is (3+4i)(22i)(3 + 4i)(2 - 2i), where ii represents the imaginary unit.

Let's multiply these two complex numbers using the distributive property (FOIL method):

(3+4i)(22i)(3 + 4i)(2 - 2i)

Step-by-step multiplication:

  1. First, multiply the first terms: 3×2=63 \times 2 = 6
  2. Multiply the outer terms: 3×2i=6i3 \times -2i = -6i
  3. Multiply the inner terms: 4i×2=8i4i \times 2 = 8i
  4. Multiply the last terms: 4i×2i=8i24i \times -2i = -8i^2 Since i2=1i^2 = -1, this becomes: 8i2=8(1)=8-8i^2 = -8(-1) = 8

Now, combine all these results:

66i+8i+86 - 6i + 8i + 8

Combine like terms: (6+8)+(6i+8i)=14+2i(6 + 8) + (-6i + 8i) = 14 + 2i

Final result:

(3+4i)(22i)=14+2i(3 + 4i)(2 - 2i) = 14 + 2i

Would you like more details on any part of this? Here are five related questions for further exploration:

  1. What is the general formula for multiplying two complex numbers?
  2. How does i2=1i^2 = -1 affect complex number calculations?
  3. Can you represent the result 14+2i14 + 2i on the complex plane?
  4. What is the geometric interpretation of multiplying complex numbers?
  5. How would you divide two complex numbers?

Tip: Always remember that when multiplying two complex numbers, use the FOIL method and simplify using the fact that i2=1i^2 = -1.

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Math Problem Analysis

Mathematical Concepts

Complex Numbers
Algebra

Formulas

(a + bi)(c + di) = (ac - bd) + (ad + bc)i

Theorems

Multiplication of complex numbers
i^2 = -1

Suitable Grade Level

Grades 10-12