f(x)= 3x^2 - x + 2

f(x - 1) = 3*(x - 1)^2 - (x - 1) + 2

f(x - 1) = 3*(x^2 - 2x + 1) - (x - 1) + 2

f(x - 1) = 3x^2 - 6x + 3 - x + 1 + 2

f(x - 1) = 3x^2 - 7x + 5

pronto