36: (Х 4) = 9

92 - (7+Х) = 43

(Х-32) + 13=9

(Х+11) - 40=21

(Х+8) : 4=120

28: (80:Х) = 7

(15*Х) - 12=18

21 + (32-Х) = 63

1) 36: 4 х = 9; 4 х = 36:9 = 4; х = 1;

2) 92 - (7+х) = 43; 7 + х = 92-43 = 49; х = 49 - 7 = 42; х = 42.

3) (х - 32) + 13 = 9; х = 32+9 - 13 = 28;

4) (х+11) - 40 = 21; х = 40 - 11 + 21 = 50;

5) (х+8) : 4 = 120; х+8 = 120 х 4 = 480; х = 480 - 8 = 472; х = 472.

6) 28 : (80 : х) = 7; 80 : х = 28 : 7 = 4; х = 80 : 4 = 20; х = 20.

7) (15 х) - 12 = 18; 15 х = 18 + 12 = 30; х = 30:15 = 2; х = 2.

8) 21 + (32-х) = 63; 32 - х = 63 - 21 = 42; - х = 42 - 32 = 10; х = - 10.