Factor completely: 9x3 - 9x2y + 4x - 4y a) (x + y)(9x2 - 4) b) (x - y)(9x2 + 4) c) (9x + y)(x - 2)(x + 2) d) (x + y)(3x - 2)(3x + 2)



step-by-step explanation:

(8 x 1) + [(4 x 16) - 3]

(8 x 1) + [4 x (16 - 3)]

(8 x 1) + [(4 x 2) - 3]

(8 x 4) + [(4 x 2) - 3](8 x 1) + [(4 x 16) - 3]

(8 x 1) + [4 x (16 - 3)]

(8 x 1) + [(4 x 2) - 3]

(8 x 4) + [(4 x 2) - 3](8 x 1) + [(4 x 16) - 3]

(8 x 1) + [4 x (16 - 3)]

(8 x 1) + [(4 x 2) - 3]

(8 x 4) + [(4 x 2) - 3](8 x 1) + [(4 x 16) - 3]

(8 x 1) + [4 x (16 - 3)]

(8 x 1) + [(4 x 2) - 3]

(8 x 4) + [(4 x 2) - 3](8 x 1) + [(4 x 16) - 3]

(8 x 1) + [4 x (16 - 3)]

(8 x 1) + [(4 x 2) - 3]

(8 x 4) + [(4 x 2) - 3]

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.  

just sum

10 + 10 = 20