When 2 negative signs are together (-)(-), the first sign is turned upright and we call it a changing sign and the 2 signs are rearranged to form a positive sign (+). The first negative sign is turned to look like this | called a changing sign. With the second negative sign the changing sign makes a positive sign (+). Example: 2 - (-1) becomes 2 + 1 = 3.
[ QUESTION 21 ]
2 - (-1) becomes 2 + 1 = 3