Answer:
2
Step-by-step explanation:
3x+15=21 (the opposite side of parallelogram is equal)
3x=21-15
3x=6
x=6/3
so x=2
AD=2
The answer is D. <span>No, it is not a valid inference because his classmates do not make up a random sample of the students in the school.</span>
The answer is B.1/2 since it is just decreasing by half ever time u go back down