ok
This is a kind of equation
To solve it, forget about the left side for a while.
On the right side there are three fractions that have the same denominator "6".
So, just add up to the numerators of the right side
2 + 2 + 1 = 5
And now, we have the same values on both sides
5/6 = 5/6
So, we have proven that this equation is true.