How do you write 2- as a signed integer?

To write -2 as a signed integer, you simply represent it as -2. In binary, using two's complement notation (which is commonly used for signed integers), you first convert the positive version, 2, to binary (which is 10 in binary for a 2-bit representation). Then, to represent -2, you invert the bits and add 1, resulting in its two's complement representation. For example, in an 8-bit system, -2 is represented as 11111110.