Not Factorable

 $\left(x-7\right)\left(x+7\right)$  

 $\left(x-7\right)^2$  

 $\left(x+7\right)^2$  

Not Factorable

 $\left(x-11\right)^2$  

 $\left(x+11\right)^2$  

 $\left(x+11\right)\left(x-11\right)$  

Not Factorable

 $\left(7x-9\right)\left(7x+4\right)$  

 $\left(7x-4\right)\left(7x+9\right)$  

 $\left(7x+6\right)\left(7x-6\right)$  

Not Factorable

 $\left(4x-15\right)\left(4x+15\right)$  

 $\left(8x-25\right)\left(2x+9\right)$  

 $\left(2x+25\right)\left(8x-9\right)$  

Not Factorable

 $\left(10x-1\right)\left(10x+1\right)$  

 $\left(100x-1\right)\left(x+1\right)$  

 $\left(50x+1\right)\left(50x-1\right)$  

Not Factorable

 $\left(8x-9\right)\left(8x+9\right)$  

 $\left(4x-3\right)\left(16x+27\right)$  

 $\left(64x+9\right)\left(x-9\right)$