First of all, notice that we have the same denominator in both fractions in the equation, which is (4a+6). This makes our task easier as we don't need to find the least common denominator to perform subtraction between fractions.
Our problem now becomes:
(a^(2)+16a-1) - (a^(2)+8a-13), which infact subtract the numerators and does not affect the denominator.
So, we subtract the like terms in the numerators:
(a^(2) - a^(2)) + (16a - 8a) + (-1 - (-13)) = 2
The fraction reduced to the whole number 2.
So, the simplified result from subtracting given rational expressions is 2.