If 9 is subtracted from two-thirds of a number, the result is 7. Find the number?

let the unknown number be denoted with 'X'
9 subtracted from two-thirds of a number, the results is 7
therefore equation is ; 9 - 2/3X = 7
then multiply the whole equation by 3 (i.e. the denominator)
9 x 3 - 2/3X x 3 = 7 x 3
27 - 2X = 21
-2X = 21 - 27
-2X = -6
X = -6 / -2 (minus sign gets cancelled)
X = 3
therefore the unknown numder denoted with 'X' is 3

TO CHECK:
9 - 2/3 x 3 = 7
9 - 2 = 7
7 = 7