1)

20-5(3х-1)=9

20-15х+5=9

-15х=9-25

-15x = -16

x = -16 : (-15)

x = 1 ¹/₁₅

2)

(4х+3)-(10х+11)=7+(13-4х)

4х+3 - 10х-11 = 7+13-4х

4x-10x+4x = 7+13-3+11

- 2x = 28

x = 28 : (-2)

x = - 14

3)

(3х-1)=35х-25

3х-35x = 1 -25

-32x = - 24

x = -24 : (-32)

x = ³/₄ = 0,75

4)

6х-5(3х+2)=5(х-1)-8

6х-15х-10 = 5x-5-8

-9x-5x = - 13+ 10

- 14x = - 3

x = - 3: (-14)

x = ³/₁₄

5)