Equivalent Rational Numbers are those numbers which have same value but are represented in different ways. The same concept can also be defined as, the equivalence of Fractions in mathematics and the numbers giving same ratio. The ratios of the two numbers have same or equivalent ratios for the ratios of the two different numeric values. To understand its concepts let's take an easy example, you can write 5/5 as 1 similarly, you can write 12/12 as 1. In this, we represented two rational numbers in different but they both are giving same result so we can define them as equivalent rational number.
Multiply the numerator and denominator of the given number by 5 then, we get 15/20 which is equivalent to 3/4.