Three polynomials are factored below, but some coefficients and constants are missing. All of the missing values of a, b, c, and d are integers.
1. x? - 8x + 15 = (ax + b)(cx + d)
2. 2x3 – 8x2 – 24x = 2x(ax + b)(cx + d)
3. 6x2 + 14x + 4 = (ax + b)(cx + d)
Fill in the table with the missing values of a, b, c, and d.