Two integers that are the same distance from zero (origin) are supposed to the opposite of each other. You can count a certain number of units to the right of the origin and a certain number of units to the left of the origin.
For example, if I count 5 units to the right of the origin then I land on the number 5. If I count 5 units to the left of the origin then I land on the number -5. These two numbers (5 and -5) have the same distances from zero.
Also, think about the absolute value--the distance from a particular number to 0.
The absolute value of -5, which is also written as |-5|, is 5 units. Similarly, the absolute value of 5, which is written as |5|, is 5 units. (This just checks what we have discussed in the previous paragraphs.)