(8/15) - (-2/3)
Start by changing the minus a negative to plus a positive.
So we have 8/15 + 2/3.
To add these two fractions together, we need a common denominator.
The common denominator is simply the
least common multiple for the two denominators.
You should find that the least common multiple is 15.
Since 8/15 already has 15 as its denominator, leave it.
To get a denominator of 15 in 2/3, we multiply top
and bottom of 2/3 by 5 to get 10/15.
So we have 8/15 + 10/5.
This simplifies to 18/15.
Now reduce to get 6/5.