These trinomials look like x² + 3x - 40 and they factor into 2 binomials such as (x + 8)(x - 5). The first term in each binomial will be "x" and the 2nd terms will be numbers that multiply so that the product is the last term of the trinomial. The middle term of the trinomial is the sum of the products of the other terms.
x² - 3x - 40 The factors of (-40) must have a sum of (-3), so the factors are (-8) & 5. (x - 8)(x + 5)
x² - 13x + 40 The factors of 40 must have a sum of (-13), so the factors are (-8) & (-5) (x - 8)(x - 5)
x² - 6x - 40 The factors of - 40 must have a sum of (-6), so the factors are (-10) & 4 (x + 4)(x - 10)
Factor each trinomial being careful to choose the correct terms. Strive for being able to factor with ease and then strive to increase your speed. Good luck and enjoy the challenge!