The trinomial 6x² + 7x - 20 may be factored using substitution.

Replace t with 6x in the answer from Exercise 79, and simplify to obtain the correct factorization of the trinomial.

Data from in Exercise 79

Factor the numerator of the expression from Exercise 78 in terms of the variable t.

Data from in Exercise 78

The first term in the numerator of the answer from Exercise 77 is now a perfect square. Let t = 6x (the square root of 36x²), and rewrite the expression.

Data from in Exercise 77

Multiply each term of 6x² + 7x - 20 by 6 (the leading coefficient). Then compensate by dividing the result by 6 (that is, write it as a fraction with denominator 6).