Answer:
The answer to your question is 8x² - 2x + 24
Explanation:
Data
EF = x² - x + 6
GF = x² + 1/2x
Perimeter
P = 2L + "W
But the condition is that the perimeter of rectangle ABCD is twice the perimeter of rectangle EFGH so.
Perimeter of EFGH = 4L + 4W
Substitution
Perimeter = 4(x² - x + 6) + 4(x² + 1/2x)
Simplification
Perimeter = 4x² - 4x + 24 + 4x² + 2x
= 8x² - 2x + 24