How can a number line you find two integers that are the same distance from zero?

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.) 

A number line can help you find two integers by looking a different direction, of each side.