the perimeter of the trapezoid is 12x+7. which represents the missing side length

Answer:
A) 3x + 1
Step-by-step explanation:
? = (12x + 7) - (3x + 3) - (2x + 1) - (4x + 2)
? = 3x + 1\
Answer:
The answer is A
Step-by-step explanation:
When looking at the question, the perimeter in total is 12x + 7. so you have to add what you already know:
3x + 3
2x + 1
4x + 2
______
9x + 6
12x + 7 - 9x + 6 = 3x + 1