let's convert the 0.2 to a fraction, and then let's put them both fractions using the same denominator.
we can convert any decimal by simply "using a denominator with as many zeros as there are decimals", so 0.2 has 1 decimal, so we use one zero, let's proceed,
now, to put those two fractions with the same denominator, we simply "multiply each other by the other's denominator", let's see how that goes,