Ответ:

1) √3х + 1 = х - 1

3х + 1 = х² - 2х + 1

3х = х² - 2х

3х - х² + 2х = 0

5х - х² = 0

х * ( 5 - х ) = 0

х = 0

х = 5

2) √2х² + 5х + 4 - 2х = 2

√2х² + 5х + 4 = 2 + 2х

2х² + 5 + 4 = 4 + 8х + 4х²

2х² + 5х = 8х + 4х²

2х² + 5х - 8х - 4х² = 0

-2х² - 3х = 0

х * ( 2х + 3 ) = 0

х = 0

х = -3/2

3) √х + 8 - √5х + 20 = 2

√х + 8 = 2 + √5х + 20

х + 8 = 4 + 4 √5х + 20 + 5х + 20

-4 √5х + 20 = 24 + 5х - х - 8

√5х + 20 = -4 - х

5х + 20 = ( 4 + х ) ²

5 ( х + 4 ) = ( 4 + х ) ²

( х + 4 ) * ( 5 - 4 - х ) = 0

( х + 4 ) * ( 1 - х ) = 0

х = -4

х = 1