To simplify the expression 30/x + 1/3 - 30/(x-3), we first need to find a common denominator for the fractions. The least common multiple of x, 3, and (x-3) is 3x(x-3).

So, rewrite the expression with the common denominator:
(30(x-3))/(x(x-3)) + (x(x-3))/(3x(x-3)) - (90)/ (x(x-3))

Now, combine the fractions:
(30x - 90 + x^2 - 3x - 90) / (3x(x-3))

Simplify the numerator:
(x^2 + 27x - 180) / (3x(x-3))

Therefore, the simplified expression is:
(x^2 + 27x - 180) / (3x(x-3))