What does it mean for two fractions to be equivalent? For two ratios to be equivalent?

Equivalent fractions and ratios mean that when simplified, they are the same one fraction or ratio. see examples below.

Step-by-step explanation:

For example, the fraction 1/2 is the same as 2/4 or 15/30 because when you simplify them, they are still 1/2. Therefore they are equivalent.

For example, the ratio 1:2 is the same as 5:10 or 10:20 since when broken down they all come down to 1:2. Hence they are equivalent.

Hope this answers your question.