如果是3x-2,还可以解,+2就难了
x^2-2*√(3x-2)=0
=>x^2=2*√(3x-2)
=>x^4=12x-8
=>x^4-12x+8=0
=>(x-2)(x^3-2x^2-4x-4)=0
=>x=2