4x =28×10
4x =280
x = 280:4
x = 70
**********
x : 4 = 10 + 28
x : 4 = 38
x = 38×4
x = 152
*****
5x = 125 : 5
5x = 25
x = 25:5
x = 5
*****
266 : x = 100 - 93
266 : x = 7
x = 266 : 7
x = 38
*******
x - 28 = 4 × 10
x - 28 = 40
x = 40+28
x = 68
******
40 - x = 28
x = 40 - 28
x = 12