Factor: t^2 - 11t + 28.

1. The last term 28 is positive and the middle term is negative, so both numbers must be negative. 2. Find two negative numbers that multiply to 28 and add to -11. 3. The pair -4 and -7 multiplies to 28 and adds to -11. 4. Use -4 and -7 as the last terms to get (t - 4)(t - 7), and check: t squared - 7t - 4t + 28 gives back t squared - 11t + 28. _Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 7 "Factoring", section 7.2 Factor Quadratic Trinomials with Leading Coefficient 1_