Answer:
(a) - Her reasoning is incorrect because you cannot divide a radical. 2 * the square root of 100. Following that math, you would get 20. Square 20 to check the answer and you get 400.
(b) - The first thing is to find a square close to 200. 14x14 is 196, which is very close. Because 200 is a little bit more than 196, we can estimate [tex]\sqrt{200}[/tex] ≈ 14
