ANSWER
24
EXPLANATION
For a matrix A of order n×n, the cofactor
of element
is defined to be

is the minor of element
equal to the determinant of the matrix we get by taking matrix A and deleting row i and column j.
Here, we have

M₁₁ is the determinant of the matrix that is matrix A with row 1 and column 1 removed. The bold entries are the row and the column we delete.

Since the determinant of a 2×2 matrix is

it follows that

so 
Answer:
I think grater then?
Step-by-step explanation:
You'll need to post the polynomial itself. The degree will be the highest exponent, the leading coefficient will be the number in front of the variable of the term with the highest exponent, then count the number of terms separated by + and - signs.
70-40= 30
30/2 = 15
40/2= 20
15 x 20 = 300

Radius / diameter as a length cannot be negative, that's why '-16' is wrong.