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

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

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

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

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

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

(14-m)*(14+m)=-2

(z-14)*(z+14)=2-

(14-cd)*(cd+14)=-()2

(2b-14)*(2b+14)=*2-

(2b-14)*(14+2b)=(*)2-

(9ab-zx)*(zx+9ab)=*()2-()2

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

(mlu+9k)*(9k-mlu)=*2-()2

(14bc3-9x)*(9x+14bc3)=*b2c6-*2

(14bc3-9x)*(9x+14bc3)=(*bc3)2-*2



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