Question

Алгебраааааааааааааа​

Answer 1

Ответ:

$3)\ \ y=\dfrac{3}{x+5}\\\\x+5=\dfrac{3}{y}\ \ ,\ \ \ x=\dfrac{3}{y}-5\ \ \ \Rightarrow \ \ \ x=\dfrac{3-5y}{y}\ \ ,\ \ \ \boxed {\ y=\dfrac{3-5x}{x}\ }\ -\ obratnaya$

$4)\ \ f(x)=\dfrac{3}{x+2}\ \ ,\ \ g(x)=3x+4\\\\\\z(x)=g(f(x))=3g(x)+4=3\cdot \dfrac{3}{x+2}+4=\dfrac{9+4x+8}{x+2}=\dfrac{4x+17}{x+2}\\\\\\\boxed{\ z(x)=\dfrac{4x+17}{x+2}\ }$