(1 point) Find the value of the constant a that makes the following function continuous on (-oo, oo). f(x)=\left\{\begin{array}{ll} \frac{5 x^{3}-15 x^{2}+10 x-30}{x-3} & \text { if } x<3 \\

3 x^{2}-x+a & \text { if } x \geq 3 \end{array}\right.