8. (a). Use the inverse of the coefficient matrix OR Cramer's rule to solve the system of linear equations below. -x - 2y + 2z = 3 2x + y - z = 3 3x - 2y + z = 7 (b). The cost to produce x units of squash is C(x) = 100x + 6000, while the revenue is R(x) = 500x Find the break-even quantity, and hence the revenue at the break-even point. 1