What is the solution to this problem?
-7/8 +Z -7/3

-\frac78 + Z - \frac73

There are no solutions unless there is an equal sign like this:

-\frac78 + Z - \frac73 = 0

So find the solution of this, you need to have Z alone on one side of the equation. To do that, you can add, subtract, multiply, divide, etc. But what you do on one side, you must do the same on the other side.

-\frac78 + Z - \frac73 = 0

Here you can simplify first by considering the fractions.

What is:

-\frac78 - \frac73 ?