Find two numbers, if their sum is (-1/3) and their difference is 18

X + y = - 0.3333333 That's the decimal equivalent of - 1/3

x - y = 18 Add these two together.

2x = 17.66666 Divide by 2

x = 8.833333

8.83333 + y = - 0.333333

y = - 0.333333 - 8.83333

y = - 9.16666

You should check this using the difference.

It will not come out exactly, but you do get a bunch of nines.