Answer:
1.5
Step-by-step explanation:
picture
The lines are reciprocal because they cross to form an X. Also 4/5 is the reciprocal of 5/4
Answer:

Step-by-step explanation:
See the attachment for better understanding..
The surface area of a regular tetrahedron is computed as the product of √3 and the square of the length of one side. The length given is 5 meters, by evaluating, we will have A = √3 (a²) = √3 (25) = 43.30. The answer is B.
7 is the third one. 8 is the first one. 9 is the second one.