If 2d = 5c, then all of the following are true except

The answer is 2/d=5/c.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

Number nine is f(x)= 40x : ) hoped i ya