26+43/57-70-21+(34)-87

The expression is $26 + 43/57 - 70 - 21 + (34) - 87$.
The term in parentheses is $(34)$, which simplifies to 34.
The expression becomes:

The division term is $\frac{43}{57}$. This fraction cannot be simplified further.

Combine all the whole numbers first:

We have $-118 + \frac{43}{57}$.
To add these, find a common denominator, which is 57.
Convert $-118$ to a fraction with denominator 57:

Now, add the fractions:

The fraction $\frac{-6683}{57}$ cannot be simplified further.

The final answer is $-\frac{6683}{57}$.