1编号:1868题型:填空题测试正确率:91.88%
化简:=______.
2编号:1030题型:填空题测试正确率:90.46%
______; ______; ______
3编号:819题型:填空题测试正确率:81.42%
已知0≤x≤3,化简+ = _________.
提醒: