Express 3 as a percent of 5

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.

Sum is 17 and their difference is 3

What is the result of adding the system of equations? 2x+y=4 3x-y=6