so basically
the square root of (5x+3)= 2 times the square root of (3x-8) or
[tex] \sqrt{5x+3}=2 times \sqrt{3x-8} [/tex]
so what you do is square both sides and get
5x+3=4 times (3x-8)
distribute
5x+3=12x-32
add 32 to both sides
5x+35=12x
subtract 5x from both sides
35=7x
divide by 7
5=x
x=5