Question

Cat este x+3 supra x+2 totul la puterea -2?
Mai exact, cum calculez ceva la puterea -2?

Answer 1

[tex]\it \left(\dfrac{a}{b}\right)^{-1} = \dfrac{b}{a} \\\;\\ \\\;\\ \left(\dfrac{a}{b}\right)^{-2} = \left[\left(\dfrac{a}{b}\right)^{-1} \right]^2=\left(\dfrac{b}{a}\right)^2 =\dfrac{b^2}{a^2}[/tex]



[tex]\it \left(\dfrac{x+3}{x+2}\right)^{-2} = \left[\left(\dfrac{x+3}{x+2}\right)^{-1} \right]^2=\left(\dfrac{x+2}{x+3}\right)^2 =\dfrac{(x+2)^2}{(x+3)^2} = \\\;\\ \\\;\\ =\dfrac{x^2+4x+4}{x^2+6x+9}.[/tex]