We will solve as follows:
[tex]w^2-12w+\alpha=0[/tex]Here alpha is the blank space, we then will solve by factoring:
[tex](w+b)(w+c)=w^2-12w+\alpha[/tex]*Two numbers that added equal -12 can be -10 and -2 and when multiplied they equal to 20, then we will have that alpha will be equal to:
[tex]w^2-12w+20=0[/tex]Then, the final expression is:
[tex]w^2-12w=-20[/tex]