Explanation:
A logarithm in one base is a constant multiple of a logarithm in any other base. Any "order of ..." specification does not include the applicable constant multiplier or the smaller order terms that may be required for an exact computation.
The concept of "order of" is similar to the concept of the degree of a polynomial. Knowing the degree of a polynomial tells you something about the "end behavior" as the function argument gets large. The specifics of the scale factor and lower-degree terms become largely irrelevant.
We will write it as a fraction in ordet to solve, that is:

We then operate as follows:

We have this, since 1 integer will be equal as a numerator divided by a denominator with equal values. Examples 1 = 2/2, 1 = 45/45, ...
(-4-(-7)) / (1-7) = (3) / (-6) = -1/2 = slope
Add all the item together:
16 + 28 + 12 + 4
=60 total items