Answer:
4x⁻¹
Explanation:
4x + 20 25 - x²
_______ ÷ _______ ↷
x² - 5x [x - 5]²
4[x + 5] [-5 + x][5 + x]
_______ ÷ _______
x[x - 5] [x - 5][x - 5]
So what we did here was factor out ALL the Greatest Common Factors [GCFs] in each denominator and numerator, and since we are dividing vertically AND horizontally, according to this, ALL [x - 5] and [x + 5] cancel each other out and all you are left with is this:
4x⁻¹
OR

This, according to the Negative Exponential Rule [Reverse], is how you rewrite it as a fraction. You bring the denominator to the numerator while ALTERING THE INTEGER SYMBOL FROM POSITIVE TO NEGATIVE:
b⁻ⁿ = 1\bⁿ
I hope this helps you out alot, and as always, I am joyous to assist anyone at any time.