The first one is not the simplest, but it is generally converted into the case that the numerator and denominator are mutually prime, that is, 48/85.

In physics problems, the result is generally required to be decimal, not fractional, while in mathematics, it is accurate, so it is generally fractional rather than fractional. )

The second question depends on the topic.

General a= expression, where there is X in the expression, the general question is written as follows:

Write the expression of a about x, find the function of a about x, and use x to represent a, etc.

(or the second question usually has suggestive questions, when x=**, find the value of a, etc. )

For specific problems, this is not a problem at all.

We just need the expression of a=x and then simplify it. Using some known conditions, a can be simplified to a constant, that is, a is a value, otherwise it is a function of X.