-1,4*(5x-3y)+4.5*(-6x-7.8y)
-7х+4.2у-27х-35.1у=-7х-27х+4.2у-35.1у=-34х-30.9у
-7х+4,2у-27х-31,5у=-34х-27,3у
-1,4*(5x-3y)+4.5*(-6x-7.8y)
-7х+4.2у-27х-35.1у=-7х-27х+4.2у-35.1у=-34х-30.9у
-1,4*(5x-3y)+4.5*(-6x-7.8y)
-7х+4,2у-27х-31,5у=-34х-27,3у