hiya, am now currently on 'equations and inequalities involving surds'

question is (2root5) + 5 = root5 - X

i'm trying to get all the x's on one side, then taking them out of the terms...
so i've got...

-X -(2root5)X

then, taking X out of it makes,

(-1 -(2root5))X

is that correct?

running through the question seems to get me the answer

-15 +(11root5)

whereas they get


so i thought that somehow i was getting the answer to -x, instead of x. but i don't know where the X changed from a positive to a negative...