Here is a list of the factoring techniques that we have discussed.

a. Factoring out the GCF

b. Factoring by grouping

c. Factoring trinomials by trial and error

d. Factoring the difference of two squares A² - B² = (A + B)(A - B)

e. Factoring perfect square trinomials A² + 2AB + B² = (A + B)², A² - 2AB + B² = (A - B)²

f. Factoring the sum of two cubes A³ + B³ = (A + B)(A² - AB + B²)

g. Factoring the difference of two cubes A³ - B³ = (A - B)(A² + AB + B²)

Fill in each blank by writing the letter of the technique (a through g) for factoring the polynomial.

x² + 7x + xy + 7y _____ .