What is the value of 3/4 + 1/16 in lowest terms

To get operations easier lets get their denominators equal, that would be converting both to 16, lets start with that:
(3/4) = (4/4)(3/4) = 4*3/*4*4 = 12/16
so, 3/4 = 12/16 they are equivalent, we can now perform the sum easily:
3/4 + 1/16
= 12/16 + 1/16
= 13/16
that is the result in the lowest terms because we cannot reduce that fraction any more.

3/4 + 1/16

Steps to adding fractions.
1) Make sure they have common denominator. 4 and 16 are the denominators, they are not the same, we need to find the Least common denominator (LCD) of the two numbers.

multiples of 4 : 4, 8, 12, 16
multiples of 16 : 16

LCD is 16.

2) Multiply the fraction that will result to the LCD. Whatever number is multiplied to the denominator should also be the number multiplied to the numerator. 
3/4 * 4/4 = 12/16

3) Add the numerators and put the sum over the LCD.
12/16 + 1/16 = (12 + 1)/16 = 13/16

4) Simplify the answer. 13/16 is already the simplest form.

3/4 + 1/16 = 13/16