we know that
case 1) -10/-7-----> 10/7-------> is not equivalent to -10/7
case 2) -3 1/7----> (-3*7+1)/7----> -20/7 ------> is not equivalent to -10/7
case 3) 1 3/7-----> (1*7+3)/7----> 10/7 ------> is not equivalent to -10/7
case 4) - -10/-7---> +10/-7----> -10/7------> is equivalent to -10/7
case 5) -1 3/7----> (-1*7+3)/7----> -4/7 ------> is not equivalent to -10/7
the answer is
- -10/-7
