I assume you mean divide using the conjugate to rationalize the denominator and express the result in standard rectangular form.

Red light is 15.1cm
yellow is 16.3cm
purple is 19.3cm
Answer:
going horizontally, 15, 3, 9, then 1, 3, 6, then 20, then, 40, 60
Step-by-step explanation:
Place value helps you divide because it helps you to know where to put the numbers