So in matt's equation, he made a mistake in the a transision from line 2 to line 3
in line 2: -4(-2)2
in line 3: -4(4)
the mistake is that -2 times 2 is not equal +4 it is equal to -4
also from lines 5 to 6 he made a mistake in order of opperations (mulit division then addition and subtract)
line 5: -10+30/5
line 6: 20/5
so he first subtracted 10 then divided, he should have divided then subtracted
so the equation should have equaled
Karen used the correct (-) times (+) property and the order of operations
so Karen is correct and Matt is wrong.
Answer: There is a strong association between age and weight.
Step-by-step explanation:
The correlation coefficient (r) is used to describe the relationship between two variables.

If r lies between -1 to -0.5 or 0.5 to 1, then there is strong association between them.
Here, Variables: Age and weight.
correlation coefficient = 0.512
That means, there is a strong association between age and weight.
4n² - 16n - 84 = 0
Multiply both sides by 1/4 :
n² - 4n - 21 = 0
Add 21 to both sides:
n² - 4n = 21
Complete the square by adding 4 to both sides:
n² - 4n + 4 = 25
(n - 2)² = 25
Solve for n :
n - 2 = ± √25
n - 2 = ± 5
n = 2 ± 5
Then n = 2 + 5 = 7 or n = 2 - 5 = -3.