One and one half minus two and five six ths

-8

Step-by-step explanation:

1 1/2 - 2 5/6 (multiply the denominator by the whole number, then add with the numerator)

3/2 - 17/6 (get the common denominator which is 6 in this situation and multiply that with the numerator)

9/6 - 17/6 = - 8