Final answer:
To rewrite the sum 4,200/x + 4,200/(x+100), find a common denominator, combine the fractions, and then simplify.
Step-by-step explanation:
To rewrite the sum of the two fractions 4,200/x and 4,200/(x+100), you would need a common denominator. A possible step in the process is to multiply the fractions by a form of 1 that will give both fractions the same denominator. For instance, you can multiply the first fraction by (x+100)/(x+100) and the second by x/x to get a common denominator of x(x+100).
Once you have both fractions over the common denominator, you can combine them into a single fraction:
(4,200(x+100) + 4,200x) / x(x+100).
Next, you would simplify the numerator by distributing and combining like terms:
(4,200x + 420,000 + 4,200x) / x(x+100) = (8,400x + 420,000) / x(x+100).
This expression can then be simplified further if needed, for example by factoring out common factors.