Solve: sqrt(2t+4)= sqrt (t-1)

 

 

 
leads to 

2t+4=t-1 
t=-5
(extraneous unless we allow for imaginary numbers) 
or 

2t+4=-(t-1) 
3t=3 
t=1
(extranoous) 

We see that over the reals this equation has no solution. Iver the complex numbers, x=-5 

:)