Sum and difference of cubes

 $\left(x-3\right)\left(x^2+3x+9\right)$  

 $\left(x+27\right)\left(x+27x+54\right)$  

 $\left(x+3\right)\left(x^2-3x+9\right)$  

 $\left(x+3\right)\left(x^2+3x+9\right)$  

PRIME

 $\left(3a-4\right)\left(3a^2+12a+16\right)$  

 $\left(a-4\right)\left(9a^2+4a+16\right)$  

 $\left(3a+4\right)\left(6a^2-12a\right)$  

 $\left(x-y\right)^3$  

PRIME

 $x\left(x^2-y^2\right)$  

 $\left(x-y\right)\left(x^2+xy+y^2\right)$  

 $\left(6x-2\right)\left(9x^2+12x+4\right)$  

 $2x\left(27x^2+4\right)$  

 $\left(6x+2\right)\left(9x^2-12x+4\right)$  

PRIME

PRIME

 $\left(x-6\right)$  

 $\left(x+6\right)$  

 $\left(x^2-9\right)$  

 $\left(25a^3-49\right)$  

 $\left(125a^3-343\right)$  

PRIME

None of the above

 $\left(16y^2+8y+1\right)$  

PRIME

 $\left(64y^2-8y+1\right)$  

 $\left(64y^2+8y+1\right)$