Math Problem Statement

To solve the given simultaneous equations using the quadratic formula:

The equations are: x-y=3 xy-5x+y=-13

Solution

We need to solve the given simultaneous equations:

  1. xy=3x - y = 3
  2. xy5x+y=13xy - 5x + y = -13

Step 1: Express yy in terms of xx from the first equation

From xy=3x - y = 3, we get: y=x3y = x - 3

Step 2: Substitute y=x3y = x - 3 into the second equation

Substituting y=x3y = x - 3 into xy5x+y=13xy - 5x + y = -13: x(x3)5x+(x3)=13x(x - 3) - 5x + (x - 3) = -13 Simplify: x23x5x+x3=13x^2 - 3x - 5x + x - 3 = -13 x27x+x3=13x^2 - 7x + x - 3 = -13 x26x3+13=0x^2 - 6x - 3 + 13 = 0 x26x+10=0x^2 - 6x + 10 = 0

Step 3: Solve x26x+10=0x^2 - 6x + 10 = 0 using the quadratic formula

The quadratic formula is: x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} Here, a=1a = 1, b=6b = -6, and c=10c = 10. Substituting these values: x=(6)±(6)24(1)(10)2(1)x = \frac{-(-6) \pm \sqrt{(-6)^2 - 4(1)(10)}}{2(1)} x=6±36402x = \frac{6 \pm \sqrt{36 - 40}}{2} x=6±42x = \frac{6 \pm \sqrt{-4}}{2} x=6±2i2x = \frac{6 \pm 2i}{2} x=3±ix = 3 \pm i

Step 4: Find yy using y=x3y = x - 3

For x=3+ix = 3 + i: y=(3+i)3=iy = (3 + i) - 3 = i For x=3ix = 3 - i: y=(3i)3=iy = (3 - i) - 3 = -i

Final Solution:

The solutions are: (x,y)=(3+i,i)and(x,y)=(3i,i)(x, y) = (3 + i, i) \quad \text{and} \quad (x, y) = (3 - i, -i)

Let me know if you want further clarification or a breakdown of any step! 😊


Related Questions:

  1. How is the quadratic formula derived?
  2. What does the presence of imaginary roots indicate about a quadratic equation?
  3. How can complex solutions be graphically represented?
  4. What are some real-world applications of complex numbers?
  5. Can we use substitution methods for other types of equations?

Tip: Always simplify equations before applying methods like the quadratic formula for easier calculations.

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Math Problem Analysis

Mathematical Concepts

Simultaneous Equations
Algebra
Quadratic Equations
Complex Numbers

Formulas

Quadratic formula x = (-b ± √(b² - 4ac)) / 2a

Theorems

Properties of Quadratic Equations
Complex Numbers in Algebra

Suitable Grade Level

Grades 10-12