Math Problem Statement

Given the equation, (2x - j5y) + 3(y + jx) = 8 - 7j. Find x.

Solution

We are given the equation:

(2xj5y)+3(y+jx)=87j(2x - j5y) + 3(y + jx) = 8 - 7j

Our goal is to find xx, where jj represents the imaginary unit (i.e., j=1j = \sqrt{-1}).

Step 1: Expand the terms on the left side

Let's expand both groups:

2xj5y+3(y+jx)2x - j5y + 3(y + jx)

Distribute the 3 across (y+jx)(y + jx):

2xj5y+3y+3jx2x - j5y + 3y + 3jx

This simplifies to:

(2x+3jx)+(3yj5y)(2x + 3jx) + (3y - j5y)

Step 2: Group real and imaginary parts

Group the real parts (involving xx and yy) and the imaginary parts (involving jj) separately:

Real part:

2x+3y2x + 3y

Imaginary part:

j(3x5y)j(3x - 5y)

So, the equation becomes:

(2x+3y)+j(3x5y)=87j(2x + 3y) + j(3x - 5y) = 8 - 7j

Step 3: Compare real and imaginary parts

We now equate the real and imaginary parts on both sides:

Real part: 2x+3y=82x + 3y = 8

Imaginary part: 3x5y=73x - 5y = -7

Step 4: Solve the system of equations

We have the system:

  1. 2x+3y=82x + 3y = 8
  2. 3x5y=73x - 5y = -7

We can solve this system using substitution or elimination. I'll use elimination here.

Multiply the first equation by 3 and the second by 2:

  1. 6x+9y=246x + 9y = 24
  2. 6x10y=146x - 10y = -14

Now subtract equation 2 from equation 1:

(6x+9y)(6x10y)=24(14)(6x + 9y) - (6x - 10y) = 24 - (-14)

This simplifies to:

19y=3819y = 38

Solving for yy:

y=2y = 2

Step 5: Substitute y=2y = 2 into one of the original equations

Substitute y=2y = 2 into the first equation 2x+3y=82x + 3y = 8:

2x+3(2)=82x + 3(2) = 8

This simplifies to:

2x+6=82x + 6 = 8

Solving for xx:

2x=2x=12x = 2 \quad \Rightarrow \quad x = 1

Final Answer:

The value of xx is 11.


Would you like more details on any step, or do you have any further questions?

Here are five related questions:

  1. How would you solve the system of equations using substitution?
  2. What happens if yy is negative in this type of equation?
  3. How does the presence of the imaginary unit jj affect the equation-solving process?
  4. Can you graph the system of equations in the real-imaginary plane?
  5. How would this problem change if the constants on the right side were complex numbers with different magnitudes?

Tip: Always group real and imaginary components separately when solving equations involving complex numbers!

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Math Problem Analysis

Mathematical Concepts

Complex Numbers
Systems of Equations
Algebra

Formulas

Expand terms: (a + b)(c + d) = ac + ad + bc + bd
Solving linear equations: ax + by = c
Group real and imaginary parts separately

Theorems

Properties of complex numbers

Suitable Grade Level

Grades 10-12