Question

elime os parenteses colchetes e chaves e reduza os termos semelhantes 2y-[-xy+(-2x+5y)-(-4xy+x)]

Answer 1

  2y-[-xy+(-2x+5y)-(-4xy+x)] =
=2y-[-xy-2x+5y+4xy-x]
=2y-[-xy+4xy-2x-x+5y]
=2y-[+3xy-3x+5y]
=2y-3xy+3x-5y
=2y-5y-3xy+3x
=-3y-3xy+3x
ou
=-3xy+3x-3y