Anyone know how to fix the error CS0619 on unity?

Convert and simplify the following sentences to conjunctive normal form (cnf): (a) (p → (q → r)) → (p → (r → q)) (b) (p ∧ q) → (¬p ↔ q) (c) ((p → q) ∧ ¬q) → ¬p

Least square fit to polynomial write a function leastsquarefit3pol that solves a linear system of equations to find a least squares fit of a third order polynomial to an experimental data set given as two row arrays. the function leastsquarefit3pol must explicitly solve a set of linear equations and cannot use polyfit. there should be no restriction on the size of the problem that can be solved.

Which of the following calculates the total from the adjacent cell through the first nonnumeric cell by default, using the sum function in its formula? -average -autosum -counta -max