Answer:
The answer to the question is 10a√2a(b + 2)
Explanation:
To know the student's error, let us calculate the perimeter from the the start.
Dimension of the rectangle is given below:
√(50a³b²) and √(200a³)
Perimeter of a rectangle = 2(L + B) = 2L + 2B
2√(50a³b²) + 2√(200a³)
2 x 5ab√2a + 2 x 10a√2a
10ab√2a + 20a√2a
Factorise
10a√2a (b + 2)
Therefore, the student made an error by adding 10ab√2a and 20a√2a together.
Note: we can not add 10ab√2a and 20a√2a together since b is missing in one of the expression.
Therefore, the answer to the question is 10a√2a(b + 2).