The number 55,220 has two 5s and two 2s. The 5s appear in the ten-thousands and thousands places, representing 50,000 and 5,000 respectively. The 2s occupy the hundreds and tens positions, corresponding to 200 and 20. In total, the 5s sum to 55,000, while the 2s add up to 220.
Answer:

Explanation step-by-step:
Let
x represent Hermione's salary prior to the raise
Given:

Therefore, the equation that expresses this relationship is

To find x, divide both sides by 1.05:


Here, 'a' relates to 0.
There are two scenarios for 'r' and 't'.
Scenario 1.
Both are positioned on the same side to the right of 'a'.
In this case, 'r' would equal 5, and 't' would equal 7.
The midpoint between 'r' and 't' is
.
Scenario 2.
If both are found to the left of 'a'.
Then 'r' would equal -5, while 't' would equal -7.
The midpoint is
.
Scenario 3.
If 'r' is right of 'a' and 't' is left of 'a'.
Thus 'r' equals 5 and 't' equals -7.
The midpoint is
.
Scenario 4.
If 'r' is left of 'a' while 't' is right of 'a'.
In this case, 'r' corresponds to -5 and 't' corresponds to 7.
The midpoint is
.
The potential midpoint coordinates for 'rt' are 6, -6, 1, and -1.