meh
ok so when have sqrt, try to square both sides

square both sides


mnus x both sides

square oth sides
x^2-2x+1=16(x-4)
x^2-2x+1=16x-64
minus (16x-4) from both sides
x^2-18x+65=0
factor
(x-5)(x-13)=0
set each to zero
x-5=0
x=5
x-13=0
x=13
x=5 and 13