Math Problem Statement

Determine the following: (5 + j7)( -3 - j8). Your answer for the real component is and the answer for the imaginary component is j .Each answer will be a whole number.

Solution

We are given the complex numbers (5+j7)(5 + j7) and (3j8)(-3 - j8). We will determine their product by expanding using the distributive property:

(5+j7)(3j8)(5 + j7)(-3 - j8)

Step 1: Expand Using Distribution

5(3)+5(j8)+j7(3)+j7(j8)5(-3) + 5(-j8) + j7(-3) + j7(-j8)

15j40j21+j2(56)-15 - j40 - j21 + j^2(56)

Step 2: Simplify Using j2=1j^2 = -1

Since j2=1j^2 = -1, we replace j2(56)j^2(56) with 56-56:

15j40j2156-15 - j40 - j21 - 56

(1556)+(j40j21)(-15 - 56) + (-j40 - j21)

71j61-71 - j61

Final Answer:

  • Real Component: -71
  • Imaginary Component: -61 (or j61j61 in the requested format)

Do you need further clarification?

Related Problems:

  1. Compute (4+j6)(2+j3)(4 + j6)(-2 + j3).
  2. Find the modulus of 5+j75 + j7.
  3. Compute the conjugate of 3j8-3 - j8.
  4. Simplify (2+j5)2(2 + j5)^2.
  5. Determine the argument (angle) of 3j8-3 - j8.

Tip: Always apply j2=1j^2 = -1 to simplify complex number multiplication!

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Math Problem Analysis

Mathematical Concepts

Complex Numbers
Multiplication of Complex Numbers
Distributive Property

Formulas

(a + jb)(c + jd) = ac + j(ad + bc) + j^2bd
j^2 = -1

Theorems

Complex Number Multiplication
Simplification Using j^2 = -1

Suitable Grade Level

Grades 9-12