Respuesta:
1-
[tex]b( {a}^{2} - ab + 1) = {a}^{2} b - {ab}^{2} + b [/tex]
2.-
[tex]( {a}^{2} + a)(a - 1) = {a}^{2} - a[/tex]
3.-
[tex](x + y)(x - y) = {x}^{2} - {y}^{2} [/tex]
