N+3/4=19/20. What is N = to?

N = 4 when added to 15/20. Because 3/4 and 19/20 have denominators that do not match, you must make their denominators the same. 4 can be multiplied by 5 to equal 20, so your denominator can match. All that is left is to multiply 3 by 5 and you are left with 15. To get from 15 to 19, you must add 4.

4/20 or 1/5. You can solve this by converting 3/4 into 15/20. The you simply subtract 19/20 by 15/20, which gives you 4/20