Final answer:
Given the question's notation, it's unclear if it intended to ask about -1 6/7, which simplifies itself, or a subtraction between -1 and 6/7, resulting in -13/7. However, neither of these interpretations yields an answer matching the options provided (a, b, c, d).
Step-by-step explanation:
To find the answer to the question -1 6-7, we need to understand that the expression seems to imply the subtraction of fractions. When subtracting fractions, it is essential to have a common denominator. Looking at the numbers given, 6 and 7, their least common multiple is 42. To convert the fractions to have a common denominator, we would multiply the numerator and denominator of each fraction by the number required to get the denominator to 42. In this case, we have: - (-1 6/7) = -1 - 6/7 = (-1 × 42/42) - (6 × 6/42) = -42/42 - 36/42 = -78/42. Now, simplify by dividing both the numerator and denominator by 6, the greatest common divisor: -78/42 ÷ 6/6 = -13/7. However, none of the answer choices is -13/7. If we look back at the initial expression, there might have been a typo in the question. Assuming the question meant to ask for -1 6/7, then: -1 6/7 is the same as: -1 - 6/7 = (-7/7) - (6/7) = -13/7 = -1 6/7 in mixed number form, which was the original expression. Since there seems to be a misunderstanding in the notation used in the original question, none of the available answer choices (a, b, c, d) match the solution -1 6/7.