A rectangular lawn measures 30 m in length and 20 m in breadth. A uniform concrete walkway of width x m is to be laid all around the lawn, outside its boundary. The combined area of the lawn and the walkway is 924 m2.
(i) Form a quadratic equation in x representing the given condition.
(ii) Solve the equation to find the width of the walkway correct to one decimal place.
(iii) Verify that your answer is reasonable in the given context.