Math Problem Statement

A curve has equation y = 2xy + 5 and a line has equation 2x + 5y = 1. The curve and the line intersect at the points A and B. Find coordinates of A and B.

Solution

We are given two equations:

  1. The curve: y=2xy+5y = 2xy + 5
  2. The line: 2x+5y=12x + 5y = 1

We are tasked with finding the points of intersection AA and BB.

Step-by-Step Solution:

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

From the line equation 2x+5y=12x + 5y = 1, we can solve for yy:

5y=12x5y = 1 - 2x y=12x5y = \frac{1 - 2x}{5}

Step 2: Substitute this expression for yy into the curve equation

The curve equation is y=2xy+5y = 2xy + 5. Substituting y=12x5y = \frac{1 - 2x}{5} into the curve equation:

12x5=2x(12x5)+5\frac{1 - 2x}{5} = 2x \left( \frac{1 - 2x}{5} \right) + 5

Step 3: Simplify the equation

First, distribute 2x2x in the right-hand side:

12x5=2x(12x)5+5\frac{1 - 2x}{5} = \frac{2x(1 - 2x)}{5} + 5 12x5=2x4x25+5\frac{1 - 2x}{5} = \frac{2x - 4x^2}{5} + 5

Now, multiply through by 5 to eliminate the denominators:

12x=2x4x2+251 - 2x = 2x - 4x^2 + 25

Step 4: Rearrange the terms

Rearrange the equation:

0=4x2+4x+240 = -4x^2 + 4x + 24 4x24x24=04x^2 - 4x - 24 = 0

Step 5: Solve the quadratic equation

Divide through by 4 to simplify:

x2x6=0x^2 - x - 6 = 0

Factor the quadratic:

(x3)(x+2)=0(x - 3)(x + 2) = 0

So, x=3x = 3 or x=2x = -2.

Step 6: Find the corresponding yy-coordinates

Substitute these xx-values into the line equation y=12x5y = \frac{1 - 2x}{5}:

  • For x=3x = 3: y=12(3)5=165=55=1y = \frac{1 - 2(3)}{5} = \frac{1 - 6}{5} = \frac{-5}{5} = -1

  • For x=2x = -2: y=12(2)5=1+45=55=1y = \frac{1 - 2(-2)}{5} = \frac{1 + 4}{5} = \frac{5}{5} = 1

Final Answer:

The points of intersection are:

  • A(3,1)A(3, -1)
  • B(2,1)B(-2, 1)

Would you like further details or clarification on any part of the solution?

Related Questions:

  1. How do you solve systems of non-linear equations algebraically?
  2. How can you verify if two curves intersect at a certain point?
  3. What techniques are useful in factoring quadratic equations?
  4. How do substitution and elimination methods differ in solving systems of equations?
  5. What are common types of curves and their properties?

Tip: Always check if a quadratic equation can be factored easily before using the quadratic formula—it can save time!

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Math Problem Analysis

Mathematical Concepts

Algebra
Systems of Equations
Quadratic Equations

Formulas

Quadratic equation formula ax^2 + bx + c = 0
Factoring quadratic equations
Solving linear equations

Theorems

Intersection of curves and lines
Properties of quadratic equations

Suitable Grade Level

Grades 10-12