Х+2 =7х9. Х-20=639. Х+700=890. Х2=14+16. Х2=27-20. 890-х=700 56-х=486. 72Х=455. Х-700=190

Найдем корни.

1) Х  + 2 = 7 х 9; 

x + 2 = 63;

x = 63 - 2;

x = 61.

2) Х - 20 = 63/9; 

x - 20 = 7;

x = 7 + 20;

x = 27.

3) Х + 700 = 890; 

x = 890 - 700;

x = 190.

4) Х * 2 = 14 + 16; 

x * 2 = 30;

x =  30/2;

x = 15.

5) Х/2 = 27 - 20; 

x/2 = 7;

x = 7 * 2;

x = 14.

6) 890 - х = 700; 

x = 890 - 700;

x = 190.

7) 56 - х = 48/6; 

56 - x = 8;

x = 56 - 8;

x = 48.

8) 72/Х = 45/5; 

72/x = 9;

9 * x = 72;

x = 72/9;

x = 8.

9) Х - 700 = 190; 

x = 190 + 700; 

x = 890.