Question

Which of the following constants can be added to x^2 - 3x to form a perfect square trinomial?

1 1/2
2 1/4
4 1/2

Answer 1

Well, if it's a perfect square then you have (x - m)^2 for some value of m. Expanding out gives x^2 - 2mx + m^2. Since the x term has a coefficient of -3, we know that -2m = -3 so m = 3/2. Then the constant term you need is m^2, which is 9/4 = 2 1/4.

Answer 2

thank you