You may want to review multiplying and dividing positive fractions first.

When you multiply or divide two signed numbers, the sign of the answer is positive if the two numbers you're given have the same sign. It's negative if they have different signs. The value is just the same as it would be if the numbers didn't have signs. For example, 1 ⁄ 2 * (−1 ⁄ 3) = −1 ⁄ 6, but (−1 ⁄ 2) * (−1 ⁄ 3) = 1 ⁄ 6. And division works the same way, so 1 ⁄ 2 / (−1 ⁄ 3) = −3 ⁄ 2 but (−1 ⁄ 2) / (−1 ⁄ 3) = 3 ⁄ 2