操作如下：光标置于需要插入字符的位置→用键盘输入“箭头”→输入法的备选 文字中就出来了“→”→用数字键选择5即可得到箭​

Step-by-step explanation:

The operation is as follows: place the cursor at the position where you want to insert characters → use the keyboard to input "arrow" → the alternative text of the input method will appear "→" → select 5 with the number keys to get the arrow

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8