Continuous and Discontinuous Functions

Examine whether the function is continuous at the points indicated against them :

f(x) `{:( = (x^2 + 18x - 19)/(x - 1)",",  "for"  x ≠ 1),(= 20",",  "for"  x = 1):}}` at x = 1

Examine whether the function is continuous at the points indicated against them:
f(x) = x³ − 2x + 1,         for x ≤ 2
      = 3x − 2,                 for x > 2, at x = 2

Examine whether the function is continuous at the points indicated against them:
f(x) = `(x^2 + 18x - 19)/(x - 1)`        for x ≠ 1

      = 20                               for x = 1, at x = 1