Question

2x+[-5x-(-2y+{-x+y})]

Answer 1

$2x+[-5x-(-2y+ \{-x+y \})] = \\ 2x+[-5x-(-2y-x+y)]=\ sacamos\ las\ llaves \ los \ signos \ NO \ cambian$

$2x+[-5x-(-2y-x+y)]=\ sacamos\ los\ parentesis\ los \ signos\ SI \ cambian$

$2x+[-5x+2y+x-y]= \\ 2x-5x+2y+x-y=$
$\ juntamos\ las\ "x"; \ juntamos \ las \ " y"$

$\\ 2x-5x+2y+x-y= \\ 2x-5x+x+2y-y= \\ \boxed{ -2x+y}$

Espero que te sirva, salu2!!!!