Ответ:

1)x=6. 2)x=6,7 или x=61/9. 3)x=4

Пошаговое объяснение:

1)((3/4)/(1/3)x+(1/4))+(2/3)=1

(3/4)/((4x+3)/12)+(2/3)=1

9/(4x+3)+(2/3)=1

9/(4x+3)+(2/3)=1

9/(4x+3)=1-(2/3)

9/(4x+3)=(1/3)

27=(4x+3)

-4x=-24

x=6

2) ((5/6)/(1/4)x-(7/12))-(1/2)=(3/12)

((5/6)/((3x-7)/12))-(1/2)=(1/4)

10/(3x-7)=(1/4)+(1/2)

10/(3x-7)=(3/4)

40=3(3x-7)

40=9x-21

-9x=61

x=61/9=6,7

3)2(1/3)/((3/8)x-(5/6))+5(2/3)=9(1/6)

(7/3)/((9x-20)/24)+(17/3)=55/6

56/(9x-20)+(17/3)=55/6

56/(9x-20)=(55/6)-(17/3)

5/(9x-20)=7/2

112=7(9x-20)

16=9x-20

-9x=-36

x=4