Length = 2w +5
Area = l * w
63 = 2w +5 *w
63 = 2w² +5w
2w² +5w-63=0
(2w-9) (w+7)
2w-9 = 0 w+7=0
2w-9+9=0+9 w+7-7=0-7
2w =9 w= -7
2w/2=9/2
w= 4.5
Since the width can not negative the width is 4.5
Length = 2(4.5) + 5
Length =9 +5
Length = 14
Check
Area = 4.5 * 14
63 = 63
The line tangent to the curve at 
has slope
Then the tangent line has equation
Even if you don't solve for the correlation coefficient, you can already solve this by process of elimination and inspection. The correlation coefficient has a positive value, therefore, it's not D. Looking at the data, you can see a trend in the values; as one data increases, the other increases as well. Therefore, the dependency of the variables is strong and the correlation coefficient must be close to 1. So, the answer is B.
There are problems like "what is the greatest number that you need" and those are the problems
