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

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

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

(1-cd)*(1+cd)=-()2

(3b-1)*(3b+1)=*2-

(3b-1)*(3b+1)=(*)2-

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

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

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

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

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

(3ab-zx)*(zx+3ab)=*()2-()2

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

(mlu+3k)*(3k-mlu)=*2-()2

(2bc3-3x)*(3x+2bc3)=*b2c6-*2

(2bc3-3x)*(3x+2bc3)=(*bc3)2-*2



×