Open Middle®
Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to construct four different quadratic expressions that can be factored as two binomials with integer coefficients and terms.
Hint
Try starting with a random c (constant term). Use this to determine b (first degree coefficient).
Answer
3x^2+4x+1 = (3x+1)(x+1)
3x^2-5x+2 = (3x-2)(x-1)
3x^2+8x-3 = (3x-1)(x-3)
3x^2-7x-6 = (3x+2)(x-3)
3x^2-5x+2 = (3x-2)(x-1)
3x^2+8x-3 = (3x-1)(x-3)
3x^2-7x-6 = (3x+2)(x-3)
Source: Giles Fox
