Решить уровнение 1. 54: x + 11 = 800 : 40 2. x * 5 +12 * 9 = 138 3. 120 + x * 3 = 375 4. 600 - 120 + x * 6 = 600 5. 1260 + 2 * x = 3000

54:х + 11 = 800 : 40
54:х+11 = 20 
54:х = 20  - 11
54:х = 9
х= 54 : 9 
х=6

54 : 6 + 11 = 800:40
9 + 11 = 20
20=20

х*5  +12*9 = 138
5х + 108 = 138
5х = 138 - 108
5х = 30
х = 30:5
х=6

6 * 5  + 12*9 = 138
30 +108 = 138
138=138

120 + х*3 = 375
х*3 = 375 - 120
3х = 255
х= 255 :3
х = 85 

120 +  85 *3 =375
120 +255=375
375=375

600 - 120 +х*6 =600
6х = 600-600 + 120
6х =120
х=120:6
х= 20

600 - 120 + 20*6 = 600
600 - 120  + 120  = 600
600=600

1260 +2х=3000
2х = 3000 - 1260
2х =1740
х=1740 :2
х= 870

1260 + 2*870 = 3000
1260 +1740=3000
3000=3000

54:х + 11 = 800 : 4054:х+11 = 20 54:х = 20  - 1154:х = 9х= 54 : 9 х=654 : 6 + 11 = 800:409 + 11 = 2020=20
х*5  +12*9 = 1385х + 108 = 1385х = 138 - 1085х = 30х = 30:5х=66 * 5  + 12*9 = 13830 +108 = 138138=138
120 + х*3 = 375х*3 = 375 - 1203х = 255х= 255 :3х = 85 120 +  85 *3 =375120 +255=375375=375

600 - 120 +х*6 =6006х = 600-600 + 1206х =120х=120:6х= 20600 - 120 + 20*6 = 600600 - 120  + 120  = 600600=600
1260 +2х=30002х = 3000 - 12602х =1740х=1740 :2х= 8701260 + 2*870 = 30001260 +1740=30003000=3000