Answer:
-25/42
Explanation:
you need to make the denominators equal, so find a number that is divisible by both 6 and 7 (i chose 42 because it’s the first number that comes to mind) you then multiply the numerator by the same number.
so -1/6 is multiplied by 7 on top and bottom to become -7/42, and -3/7 is multiplied by 6 of top and bottom to become -18/42.
then you add them together and you get -25/42
if possible you would simplify but for this one it’s not :)