Assume that the number is x:
2/3 of x take off 11 = 4x
Transform into numerical / algebraic form:
2/3 * x - 11 = 4x
Next multiply both sides by 3 to get rid of the fraction:
2 * x - 33 = 12x
Simplify:
2x - 33 = 12x
Isolate 2x by adding 33 to both sides:
2x = 12x + 33
Isolate 33 by taking 12x off both sides:
-10x = 33
Divide both sides by -10 to get the value of x:
x = 33/-10 (or x = -3.3)
Therefore the number is -3.3