Question

What did I do wrong?

Answer 1

YOU DID NOTHING WRONG ACCORDING TO WHAT YOU WROTE

`2d = f - e \\ (2d)/(2) = (f)/(2) - (e)/(2) \\ d = (f)/(2) - (e)/(2)`

RATHER MAYBE IT'S BECAUSE THEY WANT YOU TO WRITE IT IN THIS FORM.

TRY IT THIS WAY