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11 grade maths others

How do you factor quadratic equations with two variables?

Profile image of Aniket Singh
1 Year agoGrade
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1 Answer

Profile image of Askiitians Tutor Team
1 Year ago

To factor quadratic equations with two variables, we typically follow these steps:

Step 1: Identify the quadratic equation
A quadratic equation in two variables is generally of the form:

Ax^2 + Bxy + Cy^2 = 0

where A, B, and C are constants, and x and y are the two variables.

Step 2: Try factoring the equation
In some cases, the quadratic equation can be factored using a method similar to factoring a quadratic in one variable. Look for two binomials that multiply together to give you the original quadratic equation.

The factored form generally looks like:

(p * x + q * y)(r * x + s * y) = 0

where p, q, r, and s are constants to be determined.

Step 3: Apply the grouping method (if applicable)
In many cases, you can factor a quadratic equation with two variables by first splitting the middle term using a method called grouping. The goal is to rewrite the middle term (the term with both x and y) as a sum of two terms so that you can factor by grouping.

Multiply A * C (the coefficient of x^2 and y^2).
Find two numbers that multiply to give you A * C and add up to B (the coefficient of the xy term).
Rewrite the middle term (Bxy) as the sum of two terms using the two numbers found in step 2.
Factor by grouping.
Example:
Let's go through an example.

Consider the quadratic equation:

x^2 + 5xy + 6y^2 = 0

Identify A, B, and C: A = 1, B = 5, C = 6

Multiply A * C: 1 * 6 = 6

Find two numbers that multiply to 6 and add up to 5: The numbers are 2 and 3 because 2 * 3 = 6 and 2 + 3 = 5.

Rewrite the middle term: x^2 + 2xy + 3xy + 6y^2 = 0

Factor by grouping: (x^2 + 2xy) + (3xy + 6y^2) = 0 x(x + 2y) + 3y(x + 2y) = 0 (x + 3y)(x + 2y) = 0

So the factored form of x^2 + 5xy + 6y^2 = 0 is: (x + 3y)(x + 2y) = 0

Step 4: Solve for the values of x and y (optional)
To solve the factored equation, set each factor equal to zero:

x + 3y = 0 x + 2y = 0

Solving these equations gives the solutions for x and y.