Please solve a & b :)

From a rectangular sheet measuring 300mm by 200mm, equal squares of side a are cut from each of the four corners. The remaining flaps are then folded upwards to form an open box. Write an expression for the volume (V) of the box in terms of x. Fully expand all brackets mm3 Submit part 2 marks Unanswered Find the value of a that gives the maximum volume and give your answer to 2 decimal places. C mar = mm Calculate the volume to the nearest mm3. Vmax = mms