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

(3-x)*(3+x)=-2

(a-3)*(a+3)=2-

(3-cd)*(3+cd)=-()2

(4b-3)*(4b+3)=*2-

(4b-3)*(4b+3)=(*)2-

(4-m)*(4+m)=-2

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

(4-cd)*(cd+4)=-()2

(3b-4)*(3b+4)=*2-

(3b-4)*(4+3b)=(*)2-

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

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

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

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

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


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