解: (1)5﹣(﹣6)﹣(+3) =5+6﹣3 =11﹣3 =8; (2) =(﹣81)×××(﹣) =2; (3) = =×(﹣36)﹣×(﹣36)+×(﹣36) =(﹣28)﹣(﹣30)+(﹣27) =(﹣56)+30 =﹣26; (4)﹣42÷(﹣2)﹣ =﹣16÷(﹣2)﹣(﹣)×16 =8﹣(﹣2) =8+2 =10; (5)1﹣2+3﹣4+5﹣6+…+2019﹣2020 =(1﹣2)+(3﹣4)+(5﹣6)+…+(2019﹣2020) =(﹣1)+(﹣1)+…+(﹣1)(1010个﹣1相加) =﹣1010. |