(1)用适当的符号填空①∣3∣+∣4∣___∣3+4∣;②∣3∣+∣-4∣___3+∣(-4)∣;
1)用适当的符号填空
①∣3∣+∣4∣___∣3+4∣;②∣3∣+∣-4∣___3+∣(-4)∣;③∣-3∣∣4∣___∣-3-4∣④∣-3∣+∣-4∣___∣-3+(-4)∣;⑤∣0∣+∣4∣___∣0+4∣;
(2)观察后你能比较∣a∣+∣b∣和∣a+b∣的大小吗?