Look at the first ratio, if we multiply 5:20 by 3:
3(5:20) = 3*5:3*20 = 15:60
So 5:20 and 15:60 are equivalents.
Now, we have the next ratios 17:3 and 68:12.
Look at the first ratio, if we multiply 17:3 by 4, we got the next ratio:
4(17:3) = 4*17:4*3 = 68:12
Another way to find if they are equal, use cross multiply and they must have the same answer.
17:3 cross multiply by 68:12
17*12 = 204
3*68 = 208
So, the ratios are equivalents.