228.5 I believe. 14/49 is 3.5. 18+7 is 25x9 is 225. 225+3.5 would be 228.5
The question is worded a bit strangely (in my opinion anyway), but I think your teacher wants you to describe how exponents work.
Let's say we had the expression 
The base is 5 as its the bottom most value (think of something like the base of a tree or building). The exponent is 3.
The exponent of 3 tells the reader to multiply the base 5 by itself 3 times like so

With larger exponents, it becomes more tedious to write out all the repeated multiplications, which is why many calculators have an exponent button to save time.
The expression 4x^2represents 4.x.x
Hey there! :)
Answer:
29/28.
Step-by-step explanation:
Starting with:

Begin by finding a common denominator. A number that contains all of the denominators as a factor would be 28. Change each fraction to contain a denominator of 28:

Add the fractions:

Therefore, the fractions sum up to 29/28.
The answer you are looking for is: -15.
I hope this helps.