Can someone please help me ASAP!! I am stuck on my homework. 

1. Which polynomial represents a sum of cubes?
A.) x^3-64
B.) 8x^3+125
C.) 16x^3 + 1
D.) 27x^3+4
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2. Which of the following polynomials represents a difference of squares?
A.) 9x^2-49
B.) 16x^2+81
C.) 25x^2+100
D.)6x^2-121