10. find a value of r so that abt = 0, where
a = [r 1 -2] and b = [1 3 -1].

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Which expression is not a polynomial?

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.