I need help in this question about the mercy in the book the call of Wild

What is the product of the radical expression. (7-2square root) (8+2 square root)

Which best describes the strength of the correlation, and what is true about the causation between the variables? it is a weak negative correlation, and it is not likely causal. it is a weak negative correlation, and it is likely causal. it is a strong negative correlation, and it is not likely causal. it is a strong negative correlation, and it is likely causal.

What is the difference between regular convex and concave polygons