Answer:
The ratios of 3:2, 6:4, and 9:6 are all equivalent because when you divide the numerator over the denominator, you get the same result for all of them. This means that if we took 3/2 and got 1.5, and took 6/4 and got 1.5 as an answer, and took 9/6 and got 1.5 as an answer as well, we would have the same answer for all of them. This is why (in my own words) the ratios are all equivalent.