Answer:
Second option: 81y^4 - 16x^2, the difference of squares
Step-by-step explanation:
(9y^2-4x)(9y^2+4x) is a special product named difference of squares, then we can apply this formula:
(a-b)(a+b)=a^2-b^2, with a=9y^2 and b=4x, then:
(9y^2-4x)(9y^2+4x)=(9y^2)^2 - (4x)^2
(9y^2-4x)(9y^2+4x)=(9)^2 (y^2)^2 - (4)^2 (x)^2
(9y^2-4x)(9y^2+4x)=81y^(2*2) - 16x^2
(9y^2-4x)(9y^2+4x)=81y^4 - 16x^2
Answer:

Step-by-step explanation:
Blue Marbles =5
Pink Marbles =3
Total =3+5=8
Probability of drawing two marbles with replacement
=P(First Blue Marble AND Second Blue Marble)
=P(First Blue Marble) X P(Second Blue Marble)

1 dozen = 12
144 / 12 = 12 dozen
12 dozen/ 3 = 4
They need 4 times the amount of flour:
3 1/4 x 4 = 13
They need 13 cups of flour
You just multiply the option amounts :) 4x2x7x3=168