You used the wrong formula or misunderstood the question.
For more practice and review, we recommend the following resources: oxford mathematics for the new century 2a answer
Solving two or more equations at the same time. You used the wrong formula or misunderstood the question
A: Try: "New Century Mathematics 2A (Oxford) Ch 4 Ex 4A Q15 solution" . oxford mathematics for the new century 2a answer
“Solve ( 2x^2 - 5x - 3 = 0 ) by completing the square, and discuss why the method works geometrically.”