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
4x^2+4x+1 = (2x+1)(2x+1)
4x^2-6x+2 = (2x-1)(2x-2)
4x^2+8x-5 = (2x-1)(2x+5)
4x^2-3x-7 = (x+1)(4x-7)
4x^2-6x+2 = (2x-1)(2x-2)
4x^2+8x-5 = (2x-1)(2x+5)
4x^2-3x-7 = (x+1)(4x-7)
Source: Giles Fox
