Раскройте скобки: 10x+(8x-(6x+4)).
10х+(8х-(6х+4))= 10х+(8х-6х-4)=10х+8х-6х-4=(10х+8х-6х)-4=12х-4
10х+(8х-(6х+4))=10х+(8х-(6х+4))=10х+(8х-6х-4)=10х+(2х-4)=10х+2х-4=12х-4