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

(6-x)*(6+x)=-2

(a-6)*(a+6)=2-

(6-cd)*(6+cd)=-()2

(1b-6)*(1b+6)=*2-

(1b-6)*(1b+6)=(*)2-

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

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

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

(6b-8)*(6b+8)=*2-

(6b-8)*(8+6b)=(*)2-

(1ab-zx)*(zx+1ab)=*()2-()2

(1z+a)*(a-1z)=2-*2

(mlu+1k)*(1k-mlu)=*2-()2

(8bc3-1x)*(1x+8bc3)=*b2c6-*2

(8bc3-1x)*(1x+8bc3)=(*bc3)2-*2



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