Question

Write as a product: b^2*c^2-4bc-b^2-c^2+1

Answer 1

(b*c+c-1+b)*(-c+b*c-b-1)

or

(b*c + c - 1 + b)*(-c + b*c - b -1)

put both in the same order:

(bc + b + c - 1)( bc - b - c - 1)

Turn the crank:

(bc)2 + b2c + bc2 - bc -b2c -b2 - bc + b -bc2 - bc - c2 + c -bc - b - c + 1

Cancel things....

(bc)2 - bc -b2 - bc - bc - c2 -bc + 1

(bc)2 - 4bc - b2 - c2 + 1