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

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

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

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

(5b-2)*(5b+2)=*2-

(5b-2)*(5b+2)=(*)2-

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

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

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

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

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

(5ab-zx)*(zx+5ab)=*()2-()2

(5z+a)*(a-5z)=2-*2

(mlu+5k)*(5k-mlu)=*2-()2

(8bc3-5x)*(5x+8bc3)=*b2c6-*2

(8bc3-5x)*(5x+8bc3)=(*bc3)2-*2



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