`a)`
`sqrt{2x+3}=1+sqrt2` `(xge-3/2)`
`<=>(sqrt{2x+3})^2=(1+sqrt2)^2`
`<=>2x+3=1+2sqrt2+2`
`<=>2x=2sqrt2`
`<=>x=sqrt2` `(tm)`
Vậy `S={sqrt2}`
`b)`
Ta có :
`4x+sqrt{2x-1}+2=3`
`<=>sqrt{2x-1}=-4x+1`
ĐKXĐ :
`{(2x-1ge0),(),(-4x+1ge0):}`
`<=>{(2xge1),(),(-4xge-1):}`
`<=>{(xge1/2),(),(xle1/4):}` ( Vô lý )
Vậy `pt` đã cho vô nghiệm