a2-b2=(a-b)(a+b)

(8-x)*(8+x)=-2

(a-8)*(a+8)=2-

(8-cd)*(8+cd)=-()2

(4b-8)*(4b+8)=*2-

(4b-8)*(4b+8)=(*)2-

(9-m)*(9+m)=-2

(z-9)*(z+9)=2-

(9-cd)*(cd+9)=-()2

(8b-9)*(8b+9)=*2-

(8b-9)*(9+8b)=(*)2-

(4ab-zx)*(zx+4ab)=*()2-()2

(4z+a)*(a-4z)=2-*2

(mlu+4k)*(4k-mlu)=*2-()2

(9bc3-4x)*(4x+9bc3)=*b2c6-*2

(9bc3-4x)*(4x+9bc3)=(*bc3)2-*2



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