Something wrong with the equations of work

[nhmllr]

Ok, so recently I was introduced work, being
F*d=1/2*mv²
So, naturally I started playing around with it
m*d*v/t = 1/2*m*d/t*d/t
m*d²/t² = 1/2 * m*d²/t²
1 = 1/2
What did I do wrong here? Did I divide by zero somewhere or something?
(I know that these equations are not relativistically correct but this seems ridiculous)

 

[Delta2]

You assume that v=d/t which isn't correct unless v is constant which is not the case since you assume a (constant) force F is acting which changes v. If we assume F is constant then d=1/2 * v * t or v=2d/t where v here represents the final velocity after distantce d has been traveled. If you replace that v then you finally get 1=1.