Ответ:\(21+(46-11)=21+35=56\).\(53+(36+4)=53+40=93\).\(74-(51+15)=74-66=8\).\(42-(26-13)=42-13=29\).\(3\cdot6+6\cdot8=18+48=66\).\(9\cdot7-2\cdot8=63-16=47\).\(8\cdot5-3\cdot9=40-27=13\).\(7\cdot6+9\cdot6=42+54=96\).