Multiple choice

Find a quadratic equation formed by using the equations 2x + y = 6 and xy = 4.

  1. 2x2 + 6x - 4 = 0

  2. 6x2 + 2x - 4 = 0

  3. 2x2 - 6x - 4 = 0

  4. 2x2 - 6x + 4 = 0
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Given y = 6 - 2x. Substitute into xy = 4: x(6 - 2x) = 4, so 6x - 2x^2 = 4. Rearranging gives 2x^2 - 6x + 4 = 0.

AI explanation

From the first linear equation 2x + y = 6, we can express y as 6 - 2x. Substituting this into the second equation xy = 4 gives x(6 - 2x) = 4. Expanding and rearranging to zero yields 6x - 2x2 - 4 = 0, which simplifies to 2x2 - 6x + 4 = 0 when arranging the terms in standard descending order.

Keep practicing — related questions