Simple Calculus Function I am doing a course in calculus and I was given this problem :
Given that $f(x)=3x^4−6x^3+4x^2−7x+3$, evaluate $f(−2)$.
The answer is meant to be 129 according to the tutor, but no matter how many times I try and work it out I can't see how they got that answer.

Horner's method?
$$3 + x \cdot ( -7 + x \cdot (4 + x \cdot (-6 + 3\cdot x)))=$$
$$=3 + (-2 )\cdot ( -7 + (-2) \cdot (4 + (-2) \cdot (-12)))=$$
$$=3 + (-2) \cdot ( -7 + (-2) \cdot (4 + 24))=$$
$$=3 + (-2) \cdot ( -7 + (-2) \cdot 28)=$$
$$=3 + (-2) \cdot ( -7 - 56)=$$
$$=3 + (-2) \cdot (-63)=$$
$$=129$$
