What is -1 and 1/7 as decimal

First, find 1/7 as a decimal by dividing 1 by 7:

  $${\frac{{\mathtt{1}}}{{\mathtt{7}}}} = {\mathtt{0.142\: \!857\: \!142\: \!857\: \!142\: \!9}}$$

Then, add that to 1: $${\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{1}}}{{\mathtt{7}}}} = {\frac{{\mathtt{8}}}{{\mathtt{7}}}} = {\mathtt{1.142\: \!857\: \!142\: \!857\: \!142\: \!9}}$$

Finally, since this is all negative, add a negative sign in front of the number: 

- 1.1428571428571429

Rounded:

-1.143