-(3x+2y)-(5y-9x)-(2x-4y)
-(3x+2y)-(5y-9x)-(2x-4y)=-3x-2y-5y+9x-2x+4y=4x-3y
-(3х+2у)-(5у-9х)-(2х-4у)= -3х-2у-5у+9х-2х+4у=4х-3у