(about the number of culverts) If f (2x-5) is divisible by X, then f (x) is divisible by which of the following? a.x b.-x c.5-2x d.(5+x)/2 I still don't understand, Why do we need to change f (2 × 5) = A and then transform the main term to get the answer?

(about the number of culverts) If f (2x-5) is divisible by X, then f (x) is divisible by which of the following? a.x b.-x c.5-2x d.(5+x)/2 I still don't understand, Why do we need to change f (2 × 5) = A and then transform the main term to get the answer?

Let f (2x-5) = a, then a = 2x-5, x = a + 5 / 2
So choose D
It means that there are two lines, which intersect (there are only two cases of intersecting and parallel lines in two-dimensional space). One is X,
The other is 2x, so it can only intersect. Now we know that a straight line, 2x-5, and the other line must be on the line of intersection with it
The expression of that intersection is (x, f (x)). Now we only know a (a can be any number, let a = 3). Fortunately, it is related to x, x = a + 5 / 2, that is, y = a + 5 / 2, right? At this time, it is the point coordinate. A is always variable, so let it be X
y=x+5/2=f（X）