What is this ->
14y - 51=187 + 4y
is y =17 the solution to the equation ?
you need to show or write how u know ? ?
? !

So you want to get all of the unknowns on one side and all the kknowns on the other (this only works with one placeholder)
with equation you must do the same thing to both sides (except divide by 0 which is not allowed and undifined) so that the equation stays equall so

14y-51=187+4y
so add 51 to both sides
14y=238+4y
subtract 4y from both sides
10y=238
divide both sides by 10
y=23.8
(y=17 would make the equation false)

answer is y=23.8

so sorry but in this case the answwer is not 17. the first thing i did was rewrite the equation, then i moved like terms to the same sides (y's on the left numbers on the right), then i combined like terms (i did this for the y's in the previous step because i did it menatally), finally i isolated y by dividing by 10 to get the answer of y=23.8