How do you simplify $\dfrac{1}{5} + \dfrac{3}{5}$ ?

Hint:
Whenever they give an expression to simplify, if any addition or subtraction operation is present in the expression as in the given expression $\dfrac{1}{5} + \dfrac{3}{5}$ we can take the L.C.M. and simplify further to get the required answer.

Complete step by step solution:
Here in the given question they have asked to simplify the expression given by $\dfrac{1}{5} + \dfrac{3}{5}$. Here we have an additional symbol between the two values, therefore we can make use of L.C.M. (Least Common Multiple) concept to simplify the given expression.
The given question is to simplify $\dfrac{1}{5} + \dfrac{3}{5}$ , now take the L.C.M. for this expression to make simplification easier.
Therefore, we get
$\dfrac{1}{5} + \dfrac{3}{5} = \dfrac{{1 + 3}}{5}$
On simplifying the numerator further, we get
$ \Rightarrow \dfrac{1}{5} + \dfrac{3}{5} = \dfrac{4}{5}$
Now, in order to make it even simpler we do not have any common factor to make it even simple. Therefore, the $\dfrac{4}{5}$ is the simplified version of $\dfrac{1}{5} + \dfrac{3}{5}$.
We can also represent the answer we got in terms of decimal value.
In order to convert to decimal value just divide the numerator by denominator as we got in the above step, we get the value in terms of decimal form.
The decimal form of $\dfrac{4}{5}$ is $0.8$.

Therefore the simplified version of $\dfrac{1}{5} + \dfrac{3}{5}$ is $\dfrac{4}{5}$ in exact form or $0.8$ in decimal form.

Note:
In this type of question only taking L.C.M. part you may feel difficult, if you got the L.C.M. correctly then you will end up with the correct answer. It is not compulsory to convert to decimal form, you can keep the answer in any of the forms, but it should be the correct one.