ALGUIEN POR FAVOR AYUDEME A RESOLVER ESTOS 3 PROBLEMAS

Answer:
a. x^2 - 1
b. x^2 - 6x + 9
c. [tex]\dfrac{3x + 1}{x^2 + x}[/tex]
Step-by-step explanation:
a.
(x + 1)(x - 1) =
= x^2 - x + x - 1
= x^2 - 1
b.
(x - 3)^2 =
= (x - 3)(x - 3)
= x^2 - 3x - 3x + 9
= x^2 - 6x + 9
c.
[tex] \dfrac{3 + \frac{1}{x}}{1 + x} = [/tex]
[tex] = \dfrac{x(3 + \frac{1}{x})}{x(1 + x)} [/tex]
[tex] = \dfrac{3x + 1}{x + x^2} [/tex]
[tex] = \dfrac{3x + 1}{x^2 + x} [/tex]