Question 360897
Just solve:

-1/8 + y = -3/4
+1/8           +1/8

-3/4 + 1/8 = 6/8 - 1/8 = -5/8

y = -5/8

If you didn't get that step above, if you're adding to a negative you're basically decreasing the numerical value. I know that sounds weird, but think of it this way: Whereas with positive numbers 3+5=8, with negative numbers -3+5=2. It's like a ladder that's halfway underwater; even if there are more rungs under the water than above it, all the numbers under the water are less valuable. 

Hope this helps!

~IW4D