Step 1: Find the LCD (lowest Common Denominator)
When you have two fractions, we need to find a multiple of the two denominators that are equal. We do this by comparing the multiples of both denominators until we find the first instance where both denominators are the same number.In this example our denominators are 3 and 5.
For help with the art of multiplication, see Kitemans instructable on multiplication
Step 2: LCD Part 2
Step 3: LCD Part 3
Armed with this information, we can find our multipliers. In other words, what did we multiply each number by to get our LCD of 15?
Step 4: Multiplying the Fraction Parts
After the multiplication we end up with the fractions of 5/15 and 6/15
Step 5: Subtraction
When we write negative fractions, the negative number does not 'belong' to the numerator itself, but to the entire fraction. The negative number is written to the left of the fraction itself.