Question

(4x+4y)(x-2y)

Answer 1

Use the FOIL method (first, outside,insdie,last)

(4x + 4y)(x - 2y)

first -- multiply first terms in each set...4x * x = 4x^2
outside -- multiply outside terms in each set...4x * -2y = -8xy
inside -- multiply inside terms in each set...4y * x = 4xy
last -- multiply last terms in each set...4y * -2y = -8y^2
now put them all together..
4x^2 - 8xy + 4xy - 8y^2 -- combine like terms
4x^2 - 4xy - 8y^2